Teardown Report NJR 3W Ku-Band Block Up Convertor

Transcription

1 Teardown Report NJR 3W Ku-Band Block Up Convertor Overview: The National Japan Radio NJT5037F Ku-Band Block Up Convertor (BUC) is used to transmit data between ground stations and Ku-band satellites. It up converts signals in the 1 GHz range to the 14 GHz range. Because of the distance between the ground station and the satellite, three watts of output power is needed, mandating the heavy-duty heat sink design.

2 NJR 3W Ku-Band Block Up Convertor Product: NJT5037F Ku-Band Block Up Convertor (BUC) Manufacturer: New Japan Radio (NJR) Manufactured date: 2006 Purchased from: Ebay Purchase price: $50 used Country of origin: Japan Key specifications: Approximate dimensions (excluding connector): 171 x 119 x 44 mm RF Output Frequency: GHz Output 3W (+35 dbm typ.) IF Frequency: GHz. Power Requirement: +24VDC (+15 to +30 VDC). Power Consumption: 30W max High Efficiency & Low Distortion P1dB: +35 dbm min. over temperature RoHS Compliance Notes: Discontinued by manufacturer

3 Why a Zebulon Solutions Teardown? General Understand key sub-systems of existing design Understand supply chain considerations Understand manufacturing process Understand potential design pitfalls Specific to the NJT BUC Understand specific K band specific manufacturing and supply chain details such as dielectric absorbers, castings, and PCB technology Disclaimer All information contained herein is based on estimates made without access to any design documentation or proprietary information These estimates may or may not accurate No warranty is provided or implied

4 High Level View Front Back PCBA and RF Shield Die Cast heat sink to dissipate up to 30 W Ku-Band BUC Upconverts Intermediate Frequency (IF, ~1 GHz) signals to Ku-Band (~14 GHz) Up to 3W of transmitted power Sealed for use in outdoor installations

5 Enclosure Die cast main housing and lid Secondary machining for key features, tapped screw bosses, etc. White painted exterior O-rings on waveguide output and between the lid and the main housing Screws used to compress o-rings / gaskets O-rings / gaskets Casting marks

6 Inputs and Outputs Input Connector: Type N Female Output Interface: WR75 Waveguide Flange.750 x inside dimensions O-ring

7 Teardown of Internals Remove lid (8 screws) Remove cast RF shield (39 screws) Remove PCBA De-solder antenna lead and coax lead remove 4 screws PCBA

8 Dielectric absorbers are placed over crucial circuit elements to absorb certain frequencies and dampen the Q RF Shield To prevent electromagnetic interference between various RF sections of the circuitry, a cast aluminum shield is mounted over the PCBA Screws (many) are used to make good electrical contact between the shield the guard ring traces on the PCBA The shield includes many individual cavities around each circuit block to isolate each block

9 Printed Circuit Board Assembly (PCBA) Rear View PCB Fab T5037VF layers ~151.4 x x 0.65 mm Material unknown, likely an RF class fiberglass material Copper weight unknown, likely 1 oz Gold plating unknown Crystal 10B.TEW6D Antennas to waveguide (2: horizontal and vertical) Thermal vias for MMIC Power Amps (2) Copper pour (gold plated) for ground plane almost everywhere Inductors for DC-DC convertors

10 Printed Circuit Board Assembly (PCBA) Front View Mixer Eudyna 5111 Screw holes for RF shielding MMIC Power Amps (2) Eudyna FMM5059VU DC-DC Buck Convertor TI LM5641 IF and DC Power Input Printed RF filter Frequency Synthesizer Analog Devices ADF4112 Dielectric absorber Antennas to waveguide (2: horizontal and vertical)

11 Printed Circuit Board Assembly (PCBA) IF and Signal Paths The mixer up converts the input signal to the Ku-band Signal path RF path is in general brown Bias circuitry / IF path is in general green IF Path

12 Block Diagram Vertical waveguide IF Signal Conditioning MMIC Power Amp Coax input Local Oscillator Mixer RF Signal Conditioning MMIC Power Amp Horizontal waveguide DC Power and Bias Circuitry

13 Box Level Assembly Flow PCBA Screws (4) Bottom Insert PCBA into bottom and secure with screws. Coax connector Nut O-ring Waveguide insert RF shield Dielectric absorbers (7) Attach coax connector to bottom and secure with nut. Solder coax to PCBA. Insert waveguide insert and o- ring. Screws (39) Attach dielectric absorbers to RF shield Place RF shield subassembly over PCBA and secure with 39 screws Lid Gasket Place gasket into groove on bottom. Attach lid. Secure with screws. Apply label. Screws (39)

14 Bill of Materials Level Quantity Description MPN Comments 1 1 Block Up Convertor NJT5037F BUC New Japan Radio 2 1 Bottom housing subassembly 3 1 Die cast bottom W/ finned heat sink 3 1 Type N female coax connector 3 1Nut for coax 3 1 Waveguide insert 3 1 Waveguide o-ring 2 1Die cast lid 2 1 Lid gasket 2 8 Screws To attach lid 2 1 RF shield subassembly 3 1Die cast RF shield 3 7 Dielectric absorbers Assorted sizes 2 39 Screws to attach rf shield To attach RF shield 2 4 Screws To attach PCBA 2 1Label 2 1PCBA 3 1 PCB Fab T507VF Power inductors various sizes 4 1 Crystal 10B.TEW6D 4 10 Electrolytic SMT capacitors various sizes 4 1Fuse 4 2 DC regulators 4 2 MMIC Power Amp FMM5059 Eudyna 4 1 MMIC Mixer E51111 Eudyna 4 1 Waveguide antenna pin 4 2 Dielectric absorbers Assorted sizes 4 6 Discrete RF transistors 4 1 Buck convertor controller LM5642 Texas Instruments 4 1 Frequency synthesizer ADF4112 Analog Devices 4 4 Switching N-channel MOSFET A1728 NEC? 4 ~310 Misc small components Resistors, capacitors, diodes, transistors, etc

15 Supply Chain Critical elements of the supply chain would include: Die casting with secondary machining MMICs (e.g. Eudyna) RF transistors Dielectric absorbers PCB fab materials

16 Summary The NJT5037F BUC is an old design Key RF components come from Eudyna, now a division of Sumitomo Electric Dielectric absorbers are used judiciously, probably applied during design iterations Product is ruggedized and sealed for outdoor use Product is designed to dissipate excess heat Extreme attention has been paid to millimeter design techniques Despite the complexity, the product would be easy to assembly at both a PCBA and box level

17 Zebulon Solutions is a product development services company specializing in productization: turning R&D projects into manufacturing ready products. For more information, check us out at 2014 Zebulon