June-2017 www.atlantarf.com 1 Parallel Coupled Bandpass Flters (Strplne and Mcrostrp) www.atlantarf.com
Presentaton Content Parallel Coupled Bandpass Flters 1. Techncal Artcles on Parallel Coupled Bandpass Flters. 2. Descrpton of the Flter. 3. Advantages/Benefts. 4. Dsadvantages/Cautons. 5. Parastc Passband. 6. Broader Operatng Bandwdth. 7. Descrpton of Desgn Process. 8. PCflter: Computer Software. 9. PCflter: Synthess of Electrcal Crcut. 10.PCflter: Synthess of Physcal Crcut. 11.PCflter: Frequency Analyss. 12.PCflter: 6-pole Strplne Flter. 13.PCflter: 3-pole Mcrostrp Flter. 14.PCflter: 5-pole Mcrostrp Flter. 15.PCflter: 6-pole Mcrostrp Flter. 16.Summary. Illustraton of a Parallel Coupled Bandpass Flter 2
Techncal Artcles Parallel Coupled Bandpass Flters For Readers who wsh to explore a more techncal treatment of Parallel Coupled Bandpass Flters and ther physcal realzaton n mcrostrp and n strplne: Techncal artcles on Parallel Coupled Bandpass Flters n Mcrostrp: 1. Desgn Technques for Bandpass Flters Usng Edge-Coupled Mcrostrp Lnes on Fused Slca, W.H. Chlds, IEEE MTT Symposum, July 1976. 2. Broadbandng Mcrostrp Flters Usng Capactve Compensaton, I. J. Bahl, Appled Mcrowave, Aug/Sept 1989 (2 desgns). 3. Mcrostrp Flters for RF/Mcrowave Applcatons, J. Hong and M.J. Lancaster, John Wley & Sons, 2001, Page 127. 4. RF and Mcrowave Coupled-Lne Crcuts, R.K. Monga, I.J. Bahl, P. Bharta and J. Hong, Artech House, Page 285, 2007. 5. Desgn & Optmzaton of Mcrostrp Parallel Coupled Bandpass Flter at 20 GHz, P. Ran, S. Gupta and P.K. Prasad, IJARCET, Page 1808, May 2014. 6. And dozens & dozens more...... 3 Techncal artcles on Parallel Coupled Bandpass Flters n Strplne: 1. Parallel-Coupled Transmsson-Lne Resonator Flters, S.B. Cohn, IRE, MTT-6, Aprl 1958. 2. Parallel-Coupled Flter wth Improved Rejecton, Master's Thess, S. Zhongsheng, Natonal Unversty of Sngapore, Page 25, 2008. 3. Desgn and Smulaton of Edge-coupled Strplne Band Pass Flter for Ka-band Applcaton, H. Y. Wa, et al, ICTEEP, Page 97, 2012. 4. Desgn Edge-Coupled Strplne Bandpass Flter at 39GHz, IJETAE, P. Shakdwppe & K. Vyas, May 2013. 5. Desgn and Smulaton of Edge-Coupled Strplne Band Pass Flter for U-band, P. Shakdwppe, ISSR-Journals, IJIAS, Aug 2013. 6. Compact Desgn of V-band Edge-Coupled Strplne Bandpass Flter, J. Upadhyay, IJETR, July 2014.
Descrpton of the Flter Parallel Coupled Bandpass Flter A typcal planar parallel coupled bandpass flter conssts of a cascade of pars of parallel-coupled resonator lnes that are open-crcuted at both ends. The center conductor s coupled transmsson lnes are postoned parallel to each other, so that adjacent resonators are coupled along a length equal to the quarter-wavelength: λ 0 /4 at the center frequency of the flter: f 0. There are N + 1 coupled-lne sectons n an Nth-degree parallel coupled bandpass flter. 1. The physcal length of each coupled-lne center conductor (or resonator) determnes the center frequency: f 0 of the bandpass flter. 2. The lne wdth: W of each center conductor, and gap spacng: S between each coupled-lne center conductors, predomnantly effects the flter s VSWR and operatng bandwdth: BW = (f h f L )/f 0. 3. For mcrostrp parallel coupled bandpass flters, the locaton of the metal top cover above the delectrc substrate effects the RF performance of the flter. 4 RF connector λ/4 Parallel coupled lnes. Length = λ/4, 3 places.
Advantages/Benefts Parallel Coupled Bandpass Flter The advantages of Parallel Coupled Bandpass Flters n RF/mcrowave crcuts are: 1. Small physcal sze, whether constructed n mcrostrp or strplne. 2. Easy to fabrcate RF crcut traces usng conventonal photo etchng technques. 3. Absence of short crcuts (to ground plane) n ts transmsson lne s center conductors/resonators. 4. Readly packaged wth other RF crcut structures n a compact mechancal housng. 5. Produces acceptable passband nserton loss for the applcaton. 6. Produces acceptable out-of-band attenuaton for the applcaton. 5
Dsadvantages/Cautons Parallel Coupled Bandpass Flter The dsadvantages of Parallel Coupled Bandpass Flters are: 1. Parastc passband at 2 tmes the flter s center frequency: 2 x f 0. 2. Dffculty to obtan a narrow passband wth low nserton loss. 3.Radaton loss from open end-effect at each resonator: Mcrostrp. 4. As the flter s bandwdth ncreases, the gap spacng: S becomes small (< 0.002 ) n the quarterwave coupled end-sectons (Input & output coupled lnes), whch ncreases manufacturng dffcultes and worsens etchng tolerance effects. Ths narrow-gap problem often becomes unmanageable for bandwdths above 10% to 15%. 5. Materal property tolerances n the delectrc constant (Er or D k ) of the actual substrate materal has a notceable adverse effect on the flter s RF performance: It often shfts the flter s center frequency: f 0, especally n flters wth narrow fractonal bandwdths: (f h f L )/f 0. 6
Parastc Passband....Spurous Response Parallel Coupled Bandpass Flter Frequency response of a conventonal half-wave parallel coupled lne bandpass flter (red sold lne) at 100 GHz s compared to ts dealzed lumped-element band-pass counterpart (green dashed lne). The hgh frequency parallel coupled lne flter s devaton from the deal lumped element response n the parallel coupled lne flter can arse from nadequate control over resonances n the ndvdual flter sectons. 7
Broader Operatng Bandwdth Parallel Coupled Bandpass Flter As the flter s operatng bandwdth (= passband) ncreases above 10% to 15%, the gap spacng: S becomes small (< 0.002 ) n the quarterwave coupled end-sectons (Input & output coupled lnes), whch ncreases manufacturng dffcultes and worsens etchng tolerance effects. Three methods are often used to crcumvent ths dffculty: 1. The mpedance of the resonators may be ncreased, whch ncreases the requred spacngs. 2. The frst resonator may be externally coupled by nductve tappng, nstead of usng a coupler secton. Because the tghtest spacngs generally occur n the external couplng sectons: nput & output, ths approach sgnfcantly extends the useful operatng bandwdth. 3. Rasng the termnaton resstance presented to the flter by usng quarter-wave mpedance transformer sectons for the nput and output sectons. 8
9 Broader Operatng Bandwdth Parallel Coupled Bandpass Flter 5 th -order Mcrostrp Parallel Coupled Bandpass Flter wth tapped RF nput secton and tapped RF output secton. Mcrostrp Parallel Coupled Bandpass Flter wth sngle-secton mpedance transformers at RF nput and output sectons.
Descrpton of Desgn Process Parallel Coupled Bandpass Flters The desgn process for a parallel coupled bandpass flter starts wth the electrcal parameters desred for the flter (whch you select), then proceeds to calculate the electrcal crcut parameters and physcal/dmensonal parameters so the flter can be manufactured: Electrcal parameters desred for the flter, based on ts ntended applcaton n the RF crcut or RF assembly: 1. Center frequency: f 0, most often defned n Mega-Hertz: MHz. 2. Operatng bandwdth: BW = f h f L, also called: Flter s passband. 3. VSWR desred across flter s operatng bandwdth, often expressed as the ampltude rpple: L ar, db. 4. Attenuaton desred at frequences below the flter s passband or at frequences above the flter s passband; often called: Out-of-band attenuaton. 5. A delectrc substrate s selected to fabrcate the parallel coupled bandpass flter. 10
Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Select Delectrc Substrate 6. A delectrc substrate s selected based on ts compatblty wth other RF crcut structures wthn the assembly, and s based on the flter s frequency response, both across ts passband (for low nserton loss) and at ts out-of-band attenuaton/rejecton: a. The delectrc constant: E r and thckness of the delectrc substrate often determne the frequency when hgher-order modes and surface waves could launch, and these hgher-order modes/waves could adversely effect the out-of-band attenuaton produced by the flter, mostly at frequences above the flter s passband. b. The thckness of the center conductor can effect the desgn of the flter, snce a thck center conductor allows stronger couplng than a thn center conductor. As such, a thcker center conductor enables larger gap spacngs between parallel coupled resonators. Most planar flters fabrcated on flexble delectrc substrates (.e.: not ceramc or quartz) are avalable wth copper center conductors whose metal s 0.0007 thck (1/2-ounce), 0.0014 thck (1-ounce) and 0.0028 thck (2-ounce). 11
Attenuaton, db Attenuaton, db Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Number of Sectons Wth the requred/desred electrcal parameters defned, and a delectrc substrate & conductor thckness are selected, the electrcal synthess of the parallel coupled bandpass flter can proceed: 1. Determne the number of resonant sectons: N, needed n the flter based on ts desred passband response: Chebyschev or Butterworth, and ts desred out-of-band attenuaton: A at an out-of-band frequency: w 1. cosh N 1 A / 10 Lar / 10 (10 1) /(10 1 cosh ( 1 ) c 1) N log 2log A/10 10 10 10 1 / 1 c Lar 3dB f c freq Chebyshev Flter Response (Equ-Rpple passband) Butterworth Flter Response (Maxmally-flat passband) 12 f c freq
Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Lowpass Element Values 2. Calculate the lowpass prototype flter element values: g o, g 1, g 2.... g n+1 for the N-secton bandpass flter that produces the desred passband response: Chebyschev or Butterworth, and the desred out-of-band rejecton. Butterworth lowpass prototype flter crcut element values: g 0 = g n+1 = 1 g 2 sn 2 1 2n Seres R s = R L = Z o Shunt G s = G L = 1/Z o, = 1,2,3.n 13 Chebyshev lowpass prototype flter crcut element values: 2a1 4a1a g0 1 ; g1 ; gk b g where: 1 1 1 for n odd gn1 2 coth for n even 4 Lar ln(coth ) ; snh( ) 17.34 2n (2 1) a sn ; 1,2,... N 2N 2 2 b sn ; 1,2,..., N N N :Order of the flter. L ar : Maxmum passband rpple, db.
A Note about Passband Ampltude Rpple Flters syntheszed usng the Inserton Loss Method produce a passband VSWR that s related to the passband s ampltude rpple: L ar. 1. The passband s ampltude rpple s drectly related to the flter s nput/output VSWR as: 1 10 Lar 1 VSWR 1 / 10 As such, a hgher passband ampltude rpple produces a hgher passband VSWR, as shown n the table. Often, hgher passband VSWR can adversely effect the performance n communcaton systems and, therefore, t seems slly to publsh any flter s desgn whose rpple exceeds L ar > 0.5dB passband rpple = 9.64dB Return Butterworth Loss. 14 Passband Reflecton Return Rpple, Coeffcent Loss, VSWR Lar, db Γ db 0.001 0.0151734 36.38 1.03 0.005 0.0339209 29.39 1.07 0.010 0.0479576 26.38 1.10 0.020 0.0677834 23.38 1.15 0.030 0.0829696 21.62 1.18 0.040 0.0957500 20.38 1.21 0.050 0.1069902 19.41 1.24 0.060 0.1171346 18.63 1.27 0.070 0.1264472 17.96 1.29 0.080 0.1351002 17.39 1.31 0.090 0.1432132 16.88 1.33 0.100 0.1508734 16.43 1.36 0.250 0.2365145 12.52 1.62 0.500 0.3297712 9.64 1.98 0.750 0.3982523 8.00 2.32 1.000 0.4535105 6.87 2.66 2.000 0.6074888 4.33 4.10 3.000 0.7062668 3.02 5.81
15 Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Synthesze Electrcal Crcut Based on calculatons from lowpass prototype flter element values: g o, g 1, g 2.... g n+1, form the prototype flter electrcal crcut as: R s = g 0 = 1Ω L 2 =g 2 L 4 =g 4 Identcal Dual Crcuts L 1 =g 1 L 3 =g 3 L 5 =g 5 R L = g N+1 C 1 =g 1 C 3 =g 3 C 5 =g 5 g 0 = 1Ω C 2 =g 2 C 4 =g 4 R L = g N+1 = 1Ω (a) Prototype Lowpass Flter wth seres nductor nput: L 1. (b) Prototype Lowpass Flter wth shunt capactor nput: C 1. where: N = Order of the flter = Number of reactve elements n the flter. g 0 = Generator s source resstance or generator s source conductance. g = Inductance for seres nductors or capactance for shunt capactors. g N+1 = Load resstance, f g N s a shunt capactor or Load conductance, f g N s a seres nductor.
Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Frequency & Impedance Scalng Frequency scale the prototype element values to the flter s desred operatng frequency usng your center frequency: f 0 and fractonal bandwdth: (f h f L )/f 0. Impedance scale the prototype element values to the flter s desred mpedance level, often: 50 ohms. 1. The seres nductor: g k = L k s transformed nto a seres LC crcut wth element values: ' Z0gk ' L k Ck 0 0Z0 gk o Fractonal bandwdth: 2 2 21 o Center frequency: 1 or 1 2. The shunt capactor: g k = C k s transformed nto a shunt LC crcut wth element values: 2 C ' k gk Z 0 0 L Z ' k g0 0 k Bandpass flter derved from the prototype lowpass flter: R... L 5 C 5 L 3 C 3 L 1 C 1 June-2017 L N www.atlantarf.com C N R L =1... L 4 C 4 16 L 2 C 2
Descrpton of Desgn Process Parallel Coupled Bandpass Flter: Realze Physcal RF Crcut Apply dstrbuted RF crcuts to scaled bandpass flter usng Rchard s Transformatons and Kuroda s Identtes. Example: 3-pole bandpass flter. 50 L2 C2 To source network V s Transmsson lne C3 L3 Admttance nverter C1 L1 R L 50 Equvalent crcut model for parallel coupled lnes wth open-crcut at both ends. R S J 0,1 J 1,2 J 2,3 J 3,4 o/4 90 o o/4 o/4 90 o o/4 o/4 90 o o/4 o/4 /4 90 o o To R L R S Secton 1 o 4 o = wavelength at o Secton 2 o 4 Secton 3 17 o 4 o 4 Secton 4 R L An array of coupled lnes.
Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Impedance/Admttance Inverters The Admttance Inverters: J,+1 or Impedance Inverters: K,+1 n each coupled-lne secton of the flter are calculated from the lowpass prototype element values: g and the fractonal bandwdth: FBW = (f h f L )/f 0 as: For the frst coupled-lne structure: Z 0 J 0,1 Z K 0,1 For the ntermedate/mddle coupled-lne structures: For the last coupled-lne structure: 0 FBW 2 g g Z0 FBW Z0J, 1, 1to n -1 K g g Z 0 J n, n1 Z K, 1 0 n, n1 0 1 2 1 FBW 2 gngn 1 Admttance Inverter: J From these Admttance or Impedance Inverters, the Even and Odd-Mode Impedances can be calculated. 18 K, +1 Impedance Inverter: K
Descrpton of Desgn Process Parallel Coupled Bandpass Flters: Even & Odd-Mode Impedances Even and Odd-Mode Impedances: Z oe and Z oo for each coupled-lne secton n the bandpass flter are calculated from the flter s Admttance Inverters: J,+1, or Impedance Inverters: K,+1, and the characterstc mpedance of the flter: Z 0 as: From these Even and Odd-Mode mpedances, the physcal dmensons needed to realze the parallel coupled bandpass flter can be calculated: Strp Wdth (W) and gap spacng between strps (S), based on the substrate s delectrc constant, heght and strp thckness, and the method to construct: Mcrostrp or Strplne. June-2017 19 www.atlantarf.com 2 2 1, 1, ) 1, 0 ( 1, 0 1 ) ( 1 0 0 0 0 0 1, K Z K Z Z J Z J Z Z Z e ) 2 1, 0 ( 1, 0 1 ) 2 ( 1 0 0 0 0 0 1, 1, 1, K Z K Z Z J Z J Z Z Z o
Descrpton of Desgn Process Parallel Coupled Bandpass Flter: Physcal Dmensons From the Even and Odd-Mode mpedances: Z oe and Z oo, the physcal dmensons needed to realze the parallel coupled bandpass flter can be calculated: Strp Wdth: W,+1 and gap spacng between strps: S,+1, based on the substrate s delectrc constant: E r, substrate s heght and strp thckness of the center conductor: T, and the method to construct: Mcrostrp or Strplne. 20 Top vew: General structure of parallel-coupled bandpass flter that use quarter-wavelength lne resonators: N + 1 sectons.
Descrpton of Desgn Process Parallel Coupled Bandpass Flter: Strplne Constructon Photograph of a typcal 5-pole Parallel Coupled Bandpass Flter constructed n balanced strplne: 1. Metal/copper center conductor s sandwched between two delectrc materals whch has metallzaton on ts bottom surface. 2. Metallzaton on top surface of delectrc substrate s chemcally etched to produce lne wdths: W,+1 and gap spacng between strps: S,+1. Delectrc substrate wth center conductors of flter 5-pole flter = 6 sectons Top delectrc substrate (Metallzed on bottom surface) Center conductor of 5-pole Parallel Coupled strplne Bandpass flter. Sde vew of strplne flter after assembly. 21
Descrpton of Desgn Process Parallel Coupled Bandpass Flter: Mcrostrp Constructon Photograph of a typcal 5-pole Parallel Coupled Bandpass Flter constructed n mcrostrp: 1. In mcrostrp constructon, metal center conductor s exposed to envronment, whch makes the small gap spacng between strps susceptble to short crcut by stray peces of metal: FOD (Foregn Object Debrs). 2. Metallzaton on top surface of sngle delectrc substrate s chemcally etched to produce lne wdths: W,+1, and gap spacng between strps: S,+1. 3. Stand-alone delectrc substrate has metallzaton on ts bottom surface. 4. Cauton: Don t forget effects of metal top cover on RF performance of flter. Delectrc substrate wth center conductors of flter Flter s nstalled nto a metal housng to complete the assembly. 22
PCflter: Computer Software Parallel Coupled Bandpass Flter (www.atlantarf.com) offers RF/mcrowave CAE software product: PCflter to ad n the desgn of mult-secton Parallel Edge Coupled Bandpass Flters constructed n mcrostrp or n strplne: 1. Synthess of the flter s electrcal crcut: a. Lowpass prototype elements values: Chebyschev or Butterworth. b. Even and Odd-Mode Impedances: Z oe and Z oo of each secton. c. Admttance Inverters: J,+1 for each secton n the flter. 2. Synthess of dstrbuted crcut n mcrostrp or balanced strplne: a. Synthess of lne wdths: W,+1 and gap spacng between strps: S,+1. b. Synthess of physcal length of each resonator secton 3. Frequency Analyss response profle of parallel coupled bandpass flter based on physcal dmensons: a. VSWR/Return Loss, thru-path Inserton Loss and phase b. Frequency when hgher-order modes may launch. Software product: PCflter provdes the User wth full desgn capablty, from Synthess to Frequency Analyss of Parallel Edge-Coupled Bandpass Flters and ther Dstrbuted form: Mcrostrp or Strplne. 23
PCflter: Synthess of Electrcal Crcut Parallel Coupled Bandpass Flter Copyrght 2012-2017 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Software. Program: PCflter (v. 1.3) Date: 6/24/2017 Ths program performs Electrcal SYNTHESIS, Dmensonal SYNTHESIS and Frequency ANALYSIS of mult-secton Parallel Coupled Lne Bandpass Flters exhbtng a Tchebyscheff or Butterworth response across ts passband, wth constructon n Mcrostrp or Strplne. Please enter the followng Desgn Data: -Flter`s Center Frequency, MHz = 1200. -Flter`s Passband Bandwdth,MHz = 120. -Desred Bandwdth for Flter = 10.00 % -Select RESPONSE profle for your Flter: *1: Tchebyscheff (Equ-rpple) Passband Response (Default). 2: Butterworth (Maxmally Flat) Passband Response. RESPONSE profle selected = 1 Example: Data entry for synthess of electrcal crcut for User s Parallel Coupled Bandpass Flter: User enters flter s center frequency and operatng bandwdth. -Enter Passband RIPPLE Level n db: - Enter 0.01 for VSWR = 1.10; R.L. = 26.4 db. -*Enter 0.05 for VSWR = 1.24; R.L. = 19.5 db (Default). - Enter 0.10 for VSWR = 1.35; R.L. = 16.5 db. - Enter 0.20 for VSWR = 1.54; R.L. = 13.5 db. - Enter 0.50 for VSWR = 2.00; R.L. = 9.6 db. - Or a value of your choce. Enter Passband RIPPLE n db = 0.00986 -Select METHOD for enterng Number of Flter Sectons: *1: User enters Number of Flter Sectons: N (Default). 2: User enters Attenuaton at out-of-band Skrt Frequency. METHOD selected = 1 -Number of Resonate Poles: N < 12= 6 -Impedance of the System: Zo,Ohms= 50. 24 User enters passband rpple and selects number of sectons: N.
PCflter: Electrcal Crcut after Synthess Parallel Coupled Bandpass Flter PCflter (v. 1.3) Date: 6/24/2017 at 20: 2: 4Hours Copyrght 2012-2017 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of the Dstrbuted Electrcal Crcut for your Parallel Coupled Lne Bandpass Flter results n the followng Prototype Lowpass Element Values and Even-Mode & Odd-Mode Impedances: Flow = 1140.000 MHz Response = Tchebyscheff Fo = 1200.000 MHz # of Poles = 6 Fhgh = 1260.000 MHz Rpple (Am) = 0.0099 db BW = 120.000 MHz Zo of System= 50.00 Ohms BW3dB= 144.023 MHz Example: Synthess data of electrcal crcut for User s Parallel Coupled Bandpass Flter: Summary: Baselne electrcal desgn parameters for User s bandpass flter. Prototype Coupled Even & Odd Mode Normalzed Low-Pass Secton Impedances Couplng Coeff J Inverter I Elements (K,K+1) Zoe Zoo Numerc db J(K,K+1)/Yo --------------------------------------------------------------------------------------- 0 1.00000 0 1 82.51 37.63 0.44884 1 0.77970 1 2 58.79 43.53 0.09680-20.28 0.15258 2 1.35922 2 3 55.72 45.35 0.06591-23.62 0.10370 3 1.68802 3 4 55.35 45.59 0.06204-24.15 0.09760 4 1.53455 4 5 55.72 45.35 0.06591-23.62 0.10370 5 1.49516 5 6 58.79 43.53 0.09680-20.28 0.15258 6 0.70881 6 7 82.51 37.63 0.44884 7 1.10001 Source and Load Impedance = 50.00 Ohms -------------------------------------------------------------------------------------- End Secton`s External Q: Qe(1) = 7.78 and Qe( 7) = 7.78. 25 Electrcal crcut syntheszed from flter s baselne electrcal parameters.
PCflter: Synthess of Physcal Crcut Parallel Coupled Bandpass Flter PCflter (v. 1.3) Date: 6/24/2017 at 20: 2: 4Hours Copyrght 2012-2017 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of Physcal Dmensons for your Parallel Coupled Lne Bandpass Flter results n the followng desgn data: Flow = 1140.000 MHz Response = Tchebyscheff Fo = 1200.000 MHz # of Poles = 6 Fhgh= 1260.000 MHz Rpple (Am) = 0.010 db BW = 120.000 MHz Zo of System= 50.00 Ohms Er = 2.550 Constructon= Strplne B = 0.500 nches Strp Thck = 0.0017 nches Resonator Open-End Secton Lne Wdth:W Secton Gap Spacng:S Length Capactance (K) Inches MM (K,K+1) Inches MM Inches pco-farads ----------------------------------------------------------------------------------------- 1 0.2323 5.901 0 1 0.0244 0.6210 1.5397 0.1468 2 0.3408 8.656 1 2 0.1127 2.8633 1.5397 0.2027 3 0.3532 8.970 2 3 0.1636 4.1544 1.5397 0.2090 4 0.3544 9.001 3 4 0.1722 4.3747 1.5397 0.2097 5 0.3532 8.970 4 5 0.1636 4.1544 1.5397 0.2090 6 0.3408 8.656 5 6 0.1127 2.8633 1.5397 0.2027 7 0.2323 5.901 6 7 0.0244 0.6210 1.5397 0.1468 Total Length of your Bandpass Flter = 10.7782 nches. Example: Synthess data of dstrbuted crcut for User s Parallel Coupled Bandpass Flter constructed n strplne. Summary: Electrcal and physcal desgn data on User s parallel coupled flter. Synthess of dstrbuted RF crcut for User s Parallel Coupled Bandpass Flter n strplne. For Zo = 50.00 Ohms, Lne Wdth = 0.3636 nches n Er = 2.550. For Fo = 1200.00 MHz, Quarter Wavelength = 1.5397 nches. Maxmum usable operatng frequency = 4.890 GHz before possble launch of hgher-order modes. ---------------------------------------------------------------------------------------- 26
PCflter: Frequency Analyss Parallel Coupled Bandpass Flter PCflter (v. 1.3) Date: 6/24/2017 at 20: 2: 4Hours Copyrght 2012-2017 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. Frequency Analyss of your Parallel Coupled Lne Bandpass Flter results n the followng response profle: Flow = 1140.000 MHz Response = Tchebyscheff Fo = 1200.000 MHz # of Poles = 6 Fhgh= 1260.000 MHz Rpple (Am) = 0.00986 db BW = 120.000 MHz Zo of System= 50.00 Ohms SR = 5.000 u" Resstvty = 1.700 u-ohm-cm Loss Tangent = 0.00100 Example: Frequency analyss data of dstrbuted crcut for User s Parallel Coupled Bandpass Flter: Strplne. Summary: Electrcal desgn parameters for User s parallel coupled strplne flter. Frequency Input Port: S11 Input Impedance Thru Loss: S21 MHz VSWR RL,dB Phase Real Imag db Phase --------------------------------------------------------------------------------------- 1050.00 99.990-0.12 145.5 0.37 15.50-49.861-126.85 1075.00 99.990-0.17 125.6 0.61 25.65-39.466-147.35 1100.00 57.960-0.30 94.2 1.60 46.42-26.052-179.89 1125.00 8.844-1.97 18.6 146.55 204.10-7.460 101.78 1150.00 1.091-27.22 32.3 53.75 2.50-0.785-59.35 1175.00 1.065-30.08 108.4 48.93 2.91-0.647-169.32 1200.00 1.093-27.02-177.2 45.73-0.19-0.629 93.44 1225.00 1.057-31.17-104.1 49.25-2.64-0.663-3.45 1250.00 1.086-27.68-26.6 53.79-1.99-0.816-111.76 1275.00 6.499-2.69-8.3 266.33-123.15-6.171 89.61 1300.00 48.326-0.36-91.0 2.03-49.03-24.953 3.73 1325.00 86.026-0.20-123.9 0.74-26.62-38.650-30.30 1350.00 99.990-0.15-144.3 0.46-16.08-49.208-51.38 Source Impedance: Zs = 50.000 Ohms. Load Impedance: ZL = 50.000 Ohms. ----------------------------------------------------------------------------------------- 27 2-port scatterng parameters for User s Parallel Coupled Bandpass Flter based on flter s physcal dmensons: Strplne.
Example: 6-pole Strplne Bandpass Flter Parallel Coupled Bandpass Flter: Synthess of Dmensonal Data Parallel-Coupled Transmsson-Lne Resonator Flters, S.B. Cohn, IRE, MTT-6, Aprl 1958. PCflter (v. 1.3) Date: 5/28/2017 at 18:33: 3Hours Copyrght 2012-2016 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of Physcal Dmensons for your Parallel Coupled Lne Bandpass Flter results n the followng desgn data: Flow = 1140.000 MHz Response = Tchebyscheff Fo = 1200.000 MHz # of Poles = 6 Fhgh = 1260.000 MHz Rpple (Am) = 0.010 db BW = 120.000 MHz Zo of System= 50.00 Ohms Er = 2.550 Constructon = Strplne B = 0.500 nches Strp Thck = 0.0017 nches Resonator Cohn's Cohn's Cohn's Error: Cohn - PCflter, nches Secton Wdth: W Secton Spacng: S Length, Wdth: W Gap: S Length: L Wdth: W Gap: S Length: L (K) Inches (K,K+1) Inches Inches Inches Inches Inches Inches Inches Inches -------- ------ -------- ------- -------- 1 0.2323 0 1 0.0244 1.5397 0.236 0.021 1.467 0.0037-0.0034-0.0727 2 0.3408 1 2 0.1127 1.5397 0.346 0.110 1.456 0.0052-0.0027-0.0837 3 0.3532 2 3 0.1636 1.5397 0.360 0.158 1.455 0.0068-0.0056-0.0847 4 0.3544 3 4 0.1722 1.5397 0.361 0.163 1.455 0.0066-0.0092-0.0847 5 0.3532 4 5 0.1636 1.5397 0.360 0.158 1.456 0.0068-0.0056-0.0837 6 0.3408 5 6 0.1127 1.5397 0.346 0.110 1.467 0.0052-0.0027-0.0727 7 0.2323 6 7 0.0244 1.5397 0.236 0.021 0.0037-0.0034 Total Length of your Bandpass Flter = 10.7782 nches. Note: Foreshorten resonator length by: d = 0.165B = 0.165*0.5" = 0.0825" 28
Example: 6-pole Strplne Bandpass Flter Parallel Coupled Bandpass Flter: Frequency Analyss Results Parallel-Coupled Transmsson-Lne Resonator Flters, S.B. Cohn, IRE, MTT-6, Aprl 1958. Frequency analyss predcted by PCflter. 29
Example: 3-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Synthess of Dmensonal Data Desgn Technques for Bandpass Flters Usng Edge-Coupled Mcrostrp Lnes on Fused Slca, W.H. Chlds, IEEE MTT Symposum, July 1976. PCflter (v. 1.3) Date: 5/29/2017 at 13: 3:54Hours Copyrght 2012-2016 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of Physcal Dmensons for your Parallel Coupled Lne Bandpass Flter results n the followng desgn data: Flow = 11500.000 MHz Response = Tchebyscheff Fo = 11950.000 MHz # of Poles = 3 Fhgh= 12400.000 MHz Rpple (Am) = 0.200 db BW = 900.000 MHz Zo of System = 50.00 Ohms Er = 3.800 Constructon = Mcrostrp H = 0.015 nches Strp Thck = 0.0007 nches Resonator Secton Wdth: W Secton Spacng: S Length, Chlds Dmensons, Inches Error = Chlds - PCflter, Inch (K) Inches (K,K+1) Inches Inches Wdth: W Gap: S Length: L Delta W Delta S Delta L 1 0.0242 0 1 0.0040 0.1442 0.0255 0.0033 0.1385 0.0013-0.0007-0.0057 2 0.0298 1 2 0.0196 0.1429 0.0315 0.0180 0.1365 0.0017-0.0016-0.0064 3 0.0298 2 3 0.0196 0.1429 0.0315 0.0180 0.1365 0.0017-0.0016-0.0064 4 0.0242 3 4 0.0040 0.1442 0.0255 0.0033 0.1385 0.0013-0.0007-0.0057 Total Length of your Bandpass Flter = 0.5741 nches. 30
Example: 3-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Frequency Analyss Results Desgn Technques for Bandpass Flters Usng Edge-Coupled Mcrostrp Lnes on Fused Slca, W.H. Chlds, IEEE MTT Symposum, July 1976. Frequency analyss predcted by PCflter. 31
Example: 5-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Synthess of Dmensonal Data Mcrostrp Flters for RF/Mcrowave Applcatons, J. Hong and M.J. Lancaster, John Wley & Sons, 2001, Page 127. PCflter (v. 1.3) Date: 5/29/2017 at 12:15:34Hours Copyrght 2012-2016 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of Physcal Dmensons for your Parallel Coupled Lne Bandpass Flter results n the followng desgn data: Flow = 9250.000 MHz Response = Tchebyscheff Fo = 10000.000 MHz # of Poles = 5 Fhgh= 10750.000 MHz Rpple (Am) = 0.100 db BW = 1500.000 MHz Zo of System= 50.00 Ohms Er = 10.200 Constructon = Mcrostrp H = 0.025 nches Strp Thck = 0.0002 nches Resonator Secton Wdth: W Secton Spacng: S Length Hong2001 Dmensons, Inches Error = Hong - PCflter, Inch (K) Inches (K,K+1) Inches Inches Wdth: W Gap: S Length: L Delta W Delta S Delta L -------- -------- -------- ------ -------- 1 0.0136 0 1 0.0059 0.1124 0.0152 0.0063 0.1123 0.0016 0.0004-0.0001 2 0.0206 1 2 0.0194 0.1109 0.0226 0.0213 0.1091 0.002 0.0019-0.0018 3 0.0214 2 3 0.0257 0.1107 0.0234 0.0287 0.1085 0.002 0.003-0.0022 4 0.0214 3 4 0.0257 0.1107 0.0234 0.0287 0.1085 0.002 0.003-0.0022 5 0.0206 4 5 0.0194 0.1109 0.0226 0.0213 0.1091 0.002 0.0019-0.0018 6 0.0136 5 6 0.0059 0.1124 0.0152 0.0063 0.1123 0.0016 0.0004-0.0001 32
Example: 5-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Frequency Analyss Results Mcrostrp Flters for RF/Mcrowave Applcatons, J. Hong and M.J. Lancaster, John Wley & Sons, 2001, Page 127. Frequency analyss predcted by PCflter. 33
Example: 6-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Synthess of Dmensonal Data Broadbandng Mcrostrp Flters Usng Capactve Compensaton, I. J. Bahl, Appled Mcrowave, Aug/Sept 1989 (2 desgns). PCflter (v. 1.3) Date: 5/29/2017 at 11:36: 9Hours Copyrght 2012-2016 Software (www.atlantarf.com) RF/Mcrowave Computer-Aded Engneerng Desgn Data For Mult-Secton Parallel Coupled Lne Bandpass Flters. SYNTHESIS of Physcal Dmensons for your Parallel Coupled Lne Bandpass Flter results n the followng desgn data: Flow = 3800.000 MHz Response = Tchebyscheff Fo = 4000.000 MHz # of Poles = 6 Fhgh = 4200.000 MHz Rpple (Am) = 0.200 db BW = 400.000 MHz Zo of System= 50.00 Ohms Er = 3.800 Constructon = Mcrostrp H = 0.020 nches Strp Thck = 0.0002 nches Resonator Secton Wdth: W Secton Spacng: S Length Bahl6 Dmensons, Inches Error = Bahl6 - PCflter, Inch (K) Inches (K,K+1) Inches Inches Wdth: W Gap: S Length: L Delta W Delta S Delta L -------- -------- -------- ------ -------- 1 0.0316 0 1 0.0042 0.4335 0.0317 0.0043 0.4417 0.0001 0.0001 0.0082 2 0.0401 1 2 0.0216 0.4294 0.0403 0.0215 0.4327 0.0002-0.0001 0.0033 3 0.0406 2 3 0.0280 0.4291 0.0407 0.0274 0.4319 0.0001-0.0006 0.0028 4 0.0406 3 4 0.0289 0.4290 0.0408 0.0281 0.4319 0.0002-0.0008 0.0029 5 0.0406 4 5 0.0280 0.4291 0.0407 0.0274 0.4319 0.0001-0.0006 0.0028 6 0.0401 5 6 0.0216 0.4294 0.0403 0.0215 0.4327 0.0002-0.0001 0.0033 7 0.0316 6 7 0.0042 0.4335 0.0317 0.0043 0.4417 0.0001 0.0001 0.0082 34
Example: 6-pole Mcrostrp Bandpass Flter Parallel Coupled Bandpass Flter: Frequency Analyss Results Frequency analyss predcted by PCflter. 35
Summary Parallel Coupled Bandpass Flters Parallel Coupled Bandpass Flters are effectve means to allow desred RF sgnals to pass-thru a communcatons crcut, whle attenuatng RF sgnals operatng at out-of-passband frequences. A desgn process has been presented for the electrcal and dmensonal desgn of Parallel Coupled Bandpass Flters constructed n mcrostrp or n strplne transmsson lnes. s software product: PCflter s presented, whch offers the User wth a valuable and vable desgn ad for the electrcal synthess, dmensonal synthess and frequency analyss of Parallel Coupled Bandpass Flters constructed n mcrostrp or n strplne. As wth all computer-generated RF crcut desgns, the User s encouraged to confrm the physcal desgn generated by PCflter n an electromagnetc smulator, then adjust physcal dmensons (f needed), pror to manufacturng the flter. 36
, LLC LLC was founded to provde engneerng solutons, desgn software solutons, and product development solutons to the hgh-frequency RF/mcrowave ndustry n the areas of: Telecommuncatons (ground segment), Satellte (space segment) and mltary/defense (RF front-ends). Through teamwork, apples our dverse techncal experence to your project's challenges wth creatve and nnovatve solutons whle holdng ourselves accountable fo the results. Wth professonalsm and commtment to our clents, wll be there for you, both today and tomorrow. Contact, LLC by e-mal at: Servces : Servces@AtlantaRF.com Software : Sales@AtlantaRF.com Desgns : Desgns@AtlantaRF.com Or, contact by phone at: 678-445-5544, to reach our Atlanta-area offce n Georga, USA, and dscuss our support to your current or future projects & products. June-2017 www.atlantarf.com 37
Presentatons by, LLC Download varous presentatons at our webste: www.atlantarf.com : 1. Satellte: LEO, MEO & GEO. 2. Antennas: An Overvew. 3. Lnk Budget: Gettng Started. 4. Lnk Budget: Dgtal Modulaton Part 1 (Overvew & M-ASK). 5. Lnk Budget: Dgtal Modulaton Part 2 (M-FSK). 6. Lnk Budget: Dgtal Modulaton Part 3 (M-PSK & QAM). 7. Lnk Budget: Error Control & Detecton. 8. Multple Access Technques: FDMA, TDMA and CDMA. 9. Inserton Loss: Double Rdge Wavegude. 10.RF Flters: An Overvew. 11.Mult-Secton Symmetrcal Drectonal Couplers. 12.Parallel Coupled Bandpass Flters. Vst our webste often as presentatons are added for your vewng pleasure. 38