Receiver Architectures

Transcription

1 27/Dec/26 1

2 Receiver Archiecures Image-Rejec Receivers Shif-by-9 o For narrowband signal: sin cos +j /2 +j (a) T / 4 X = j j /2 G( ) = j sgn( ) 1/2 (b) Figure 5.23 Shif by 9 o in (a) ime and (b) frequency domain. 1/2 2

3 RC-CR nework Receiver Archiecures mag( V ) V ou2 V ou1 C R V in V ou1 R C V ou2 ( ) phase V π / 2 V ou1 V ou2 Figure 5.24 Shif-by-9 o nework. 3

4 Quadraure Signal Generaion Receiver Archiecures LO in+ LO I + D Q LO I LO Q+ LO in Q LO in LO I D Q LO Q LO Q Q Polyphase filer Divide-by-2 couner 4

5 Receiver Archiecures Image-Rejec Receivers Harley Archiecure Single-sideband (SSB) modulaion A 9 o C RF Inpu sin LO cos LO IF Oupu Figure 5.25 Harley image-rejec receiver. B 5

6 Receiver Archiecures Image-Rejec Receivers Harley Archiecure X A () +j /2 RF Inpu +j /2 LO j /2 j /2 Image LO X B () Desired Channel X C () 9 o 9 o IF Oupu Figure 5.26 Graphical analysis of Harley archiecure. 6

7 Receiver Archiecures Image-Rejec Receivers Harley Archiecure RF Inpu sin LO cos LO R C R IF Oupu Figure 5.27 Image-rejec receiver wih spli phase shif sages. C Image rejecion raio ( IRR) = ( A/ A) θ A A R R + C C 7

8 Receiver Archiecures Image suppression vs. ampliude/phase error Phase Error (degree) dBc -36dBc -38dBc -3dBc -34dBc -22dBc -24dBc -26dBc -28dBc -32dBc -2dBc Ampliude Error (db) 8

9 Receiver Archiecures Image-Rejec Receivers Weaver Archiecure A C RF Inpu sin 1 cos 1 sin 2 cos 2 + IF Oupu B D Figure 5.28 Weaver image-rejec receiver. 9

10 Receiver Archiecures Image-Rejec Receivers Weaver Archiecure X A () +j j RF Inpu +j j 1 +j /2 2 Image j /2 Desired Channel X C () X B () +1/2 +1/ Figure 5.29 Graphical analysis of Weaver archiecure. X D () 1

11 Receiver Archiecures Image-Rejec Receivers Weaver Archiecure RF Inpu Secondary Image 1 in 2 2 in + 21 Desired Channel Firs IF in 1 in 1 Second IF in 1 2 Figure 5.3 Problem of secondary image in Weaver archiecure. 11

12 Digial-IF Receivers BPF Receiver Archiecures cos LO BPF Precision Lineariy DR Power A ADC Figure 5.31 Digial-If receiver. Muliplier sin cos Muliplier Digial Sinewave Generaor I Q fif f BPF ADC f LO Figure 5.32 Sampling If archiecure. f S fif fs f 12

13 Subsampling Receivers Receiver Archiecures RF Signal Sampling Signal Oupu Signal (a) (b) Figure 5.33 Subsampling in (a) ime and (b) frequency domains. 13

14 Receiver Archiecures R on Vin C S (a) Vou N 2 mn (b) Figure 5.34 (a) Equivalen circui of a sampler, (b) aliasing of noise in subsampling. 14

15 Transmier Archiecures /RF Inerface Signal Signal Condiioning f drif wih ime & emperaure Modulaed VCO Signal Figure 5.35 /RF inerface in an FM sysem. Daa Serial/Parallel Condiioning sin LO cos LO Modulaed Signal Figure 5.36 /RF inerface in a quadraure modulaion sysem. 15

16 /RF Inerface Transmier Archiecures IROM DAC A Daa Address Generaor sin LO cos LO Modulaed Signal QROM DAC B Figure 5.37 pulse shaping. 16

17 /RF Inerface Daa Transmier Archiecures Gaussian Filer sine ROM DAC sin LO cos LO Modulaed Signal cosine ROM DAC Figure 5.38 pulse shaping in GMSK sysems. 17

18 PA/Anenna Inerface Transmier Archiecures Direc-conversion Transmiers I Duplexer TX RX Loss:2~3dB TX RX Loss:.5~1dB cos C sin C Maching Nework Q Figure 5.39 Direc-conversion ransmier. Duplexer 18

19 Transmier Archiecures Direc-conversion Transmiers I injecion pulling or injecion locking PA VCO BPF Q LO Figure 5.4 Leakage of PA oupu o oscillaor. 19

20 Transmier Archiecures Direc-conversion Transmiers I VCO 1 VCO 2 1 BPF Phase Splier BPF PA 2 Q Figure 5.41 Direc-conversion ransmier wih offse LO. 2

21 Two-Sep Transmiers Transmier Archiecures I Q sin 1 cos BPF cos 2 BPF PA Figure 5.42 Two-sep ransmier. 21

22 OPLL opology Transmier Archiecures Easy realized bu more complex I Q Modulaor + Loop Filer VCO PA LO 2 BPF LO 1 22

23 Transmier Archiecures PLL Topology Reference Frequency + Loop Filer VCO PA Divider Daa Pre-disorion Sigma-dela Modulaor Open-Loop modulaion Only suiable for low accuracy requiremen Daa VCO Buffer PA 23

24 Transceiver Performance Tess 5dBm 49dBm 45dBm 35dBm 23dBm 98dBm 98dBm 98dBm f f Figure 5.43 Typical blocking ess in GSM. (a) In-band inermodulaion, (b) ou-of-band and second-order inermodulaion, (c) ou-of-band cross modulaion. f 24 Desired Channel Unmodulaed Inerferer Modulaed Inerferer Modulaed Inerferer Modulaed Inerferer Desired Channel Modulaed Inerferer f IF Desired Channel ( a) ( b ) (c )

25 Transceiver Performance Tess 1 db/div. 1 khz/div. Figure 5.44 Modulaion mask in GSM along wih ypical signal specrum. 25

26 Moorola s FM Receiver Case Sudies Maching Nework 1.7 MHz Ceramic Filer VCO Conrol Volage X-Osc MHz 455 khz Limier Ceramic Filer FM Demodulaor Audio Oupu Figure 5.45 Simplified archiecure of MC

27 Philips Pager Receiver Case Sudies Maching Nework Differenial Cascode LNA Limier I 9 o Freq. Mul. X-Osc. FSK Demod. Daa Q Limier Figure 5.46 Simplified archiecure of UAA28T. 27

28 Case Sudies Philips DECT Transceiver UAA277 DAC 45 o V LO2 BPF Maching Nework 9 o V LO1 BPF SA o DAC BPF Limier PA Buffer VCO TX Daa BFG54 Figure 5.47 Philips DECT ransceiver. GFSK Demod. Daa 28

29 Philips DECT Transceiver Receive Case Sudies Blind Slo VCO TX in Closed Loop Transmi VCO TX in Open Loop Figure 5.48 Timing diagram illusraing blind slo operaion. 29

30 Case Sudies Lucen Technologies GSM Transceiver Duplexer LNA PA Image Rejec Filer 71 MHz SAW Filer 117 MHz VCO 1 VCO 2 9 o o o 4 VCO 3 I I Q 284 MHz Q Figure 5.49 Lucen Technologies GSM ransceiver. 3

31 Philips GSM Transceiver Case Sudies LNA Image Rejec Filer LNA Image Rejec Filer 4 MHz SAW Filer Programmable Gain Duplexer PA Buffer SSB Mixer V LO1 IF Level Conrol V LO2 9 o I Q 4 MHz I LC Filer Q Figure 5.5 Philips GSM ransceiver. 31