SWRU553A September   2019  – February 2020 AWR1243 , AWR2243

 

  1.   AWRx Cascaded Radar RF Evaluation Module (MMWCAS-RF-EVM)
    1.     Trademarks
    2. 1 Getting Started
      1. 1.1 Introduction
      2. 1.2 EVM Revisions
      3. 1.3 Key Features
      4. 1.4 What is Included
        1. 1.4.1 Kit Hardware Contents
        2. 1.4.2 mmWave Studio and Matlab Post Processing
    3. 2 Hardware Description
      1. 2.1 Block Diagram
      2. 2.2 Attaching the MMWAVCAS-RF-EVM to the MMWAVCAS-DSP-EVM
      3. 2.3 Power Status LED Indicators
      4. 2.4 Reset LED Indicators
      5. 2.5 Connectors
        1. 2.5.1 Host Board Connectors(J4, J5)
        2. 2.5.2 Bench Power Connector(J6)
        3. 2.5.3 20 GHz LO Debug Connector (J3)
        4. 2.5.4 AWR OSC_CLKOUT Debug Header (J2)
        5. 2.5.5 AWR Debug Headers (J1_1, J1_2, J1_3, J1_4)
      6. 2.6 Antennas
        1. 2.6.1 TX and RX Antenna Arrays
        2. 2.6.2 PCB Antenna Element
          1. 2.6.2.1 RX Antenna Element Performance
          2. 2.6.2.2 TX Antenna Element Performance
        3. 2.6.3 Virtual Antenna Array
    4. 3 Design Files and Software Tools
      1. 3.1 Hardware Collateral
      2. 3.2 Software, Development Tools, and Example Codes for MMWCAS-RF-EVM
      3. 3.3 Critical AWRx Setup Notes
        1. 3.3.1 LDO Bypass Requirement
    5. 4 PCB Dimensions and Mounting Information
    6. 5 PCB Storage and Handling Recommendations
    7. 6 References
    8. 7 Regulatory Information
  2.   Revision History

4 PCB Dimensions and Mounting Information

The field of view of the radar sensor is orthogonal to the PCB top layer where the etched antenna are placed. See the above antenna sections for more details on the antenna element gain patterns.

Mounting to the MMWCAS-DSP-EVM is accomplished through the 4, plated, through-holes in each corner of the PCB. An optional pattern of 4, plated through-hole are provided in the same lateral area as the AWRx devices and are meant to support a user-designed heat-sink plate across theAWRx packages.

swru553-cascade-rf-design-spec-diagrams-mechanical2.pngFigure 29. MMWCAS-RF-EVM Overall Mechanical Dimensions and Mounting Drill Dimensions

The MMWCAS-RF-EVM PCB is composed of an 8-layer, heterogenous, sequential lamination, stack-up. Rogers RO3003 is used for the Layer 1 RF GCPW routing, etched antenna structtures and the 20 GHz LO splitters. RO4450F prepreg and RO4835 LoPro are used to create Stripline routing on Layer 3 for 20 GHz LO distribution. The lower 4 core and prepreg layers are in Isola 370HR. These layers are dedicated to power distribution and high-speed digital routing.

swru553-cascade-rf-design-spec-diagrams-drillstack1.pngFigure 30. MMWCAS-RF-EVM PCB and Drill Stack-Up Table

Three via types are utilized throughout the design:

  • L1-L8, 12.2mil drill, 22.4 mil pad - primary via used throughout the design for power and high-speed digital routing
  • L1-L2, 5.9 mil drill, 13.77 mil pad (blind, micro-via) - L1 to L2 ground plane shorting for RF and LO routing distribution
  • L1-L3, 12 mil drill, 24 mil pad, (backdrilled up to L3) - 20 GHz LO distribution L1 GCPW to L3 Stripline transition