High Performance Software Defined Radio

Transcription

1 High Performance Software Defined Radio Alex LP/HP Filter Board Testing September 2011 Scotty Cowling, WA2DFI 2011 TAPR/ARRL Digital Communications Conference

2 Alpha 1 boards funded by developers, August 2007 Alpha 2 boards funded by T APR, January 2008 Alpha 3 board funded by T APR, March 2008 All pre-production testing complete, March 2011 PCBs fabricated and deli vered April 2011 Cables, enclosure and custom panels done, May 2011 Production run complete, July 2011 Testing complete, September 2011 Status: Fully assembled/tested and bare PCBs, enclosure, cables, silk screened end panels available from TAPR now

3 Alex TX-LPF Board

4 Alex RX-HPF Board

5 Alexiares RF Bandpass Filters XV RX IN X2 1 BNC Alex RX Testing Test Fixture ALEX RX K15 BIT7 XV_IN TEST FIXTURE 20dB Attenuator K18 10dB Attenuator K BIT9 K1 K2 1.5MHz HPF: 1dB 1.75MHz (7th order HPF) 55MHz LPF: 1dB 55.8MHz (7th order LPF) 1 BNC OUT to RX X1 RX2 IN X3 RX1 IN X4 1 BNC 1 BNC RF OUT PUT TO MERCURY RX IN 1 X6 SMB K16 K19 K20 BIT6 BIT5 BIT4 RX2_IN RX1_IN RX1_OUT BIT2 20dB BIT1 10dB BIT10 BIT11 BIT14 BIT13 K3 K5 K6 K9 K4 K6 K8 K10 6.5MHz HPF: 1dB 6.4MHz (7th order HPF) 9.5MHz HPF: 1dB 9.4MHz (7th order HPF) 13MHz HPF: 1dB 13.4MHz (7th order HPF) 20MHz HPF: 1dB 18.8MHz (7th order HPF) RX1 OUT X5 1 BNC 6M BIT12 K11 K12 6M preamp: 1dB 50MHz/52MHz 2dB 49MHz/53MHz (bandpass) K13 K14 Bypass BIT0 RX_RED_LED BYPASS BIT3 RED D3 YEL D2 BIT15 RX_YEL_LED BIT0 is LSB (first serial data bit) BIT15 is MSB (last serial data bit) Bits are all active HIGH to engage relay or light LED NOT USED BIT8 N/C

6 Alex RX Testing Test Fixture

7 Alex RX Testing Test Setup UG-491/U with one ferrule removed (5 places) 10-pin ribbon cable ALEX RX TEST FIXTURE BOARD (COMPONENT SIDE DOWN) X5 (BOTTOM) X5 J1 (BOTTOM) X6 X4 (BOTTOM) X4 X6 (BOTTOM) J1 LOAD=J1 PIN 6 X3 (BOTTOM) X3 C94 6M TUNE LOAD=J1 PIN 5 X2 (BOTTOM) X2 X1 (BOTTOM) X1 ALEX RX BOARD UNDER TEST (COMPONENT SIDE UP) +27dBm -43dBm MERCURY J2 J3 PENNYLANE P4 J5 70dB ATEN 1W J6 ATLAS BUS NOTE: MAGISTER AND PC CONNECTION NOT SHOWN

8 Alex RX Testing Test Setup

9 Alexiares RF Bandpass Filters Alex RX Testing - Test Station

10 Alexiares RF Bandpass Filters Alex TX Testing - Test Station

11 Alex RX Testing Filter Selection Problem: Alex uses a single SPI interf ace for both RX and T X boards One select pin f or Alex-RX and a different one for Alex-TX Since the test f ixture is made f rom the same board as the board under test, both boards use the same select pin!

12 Alex RX Testing Filter Selection Solution: Cut-and-jump the test fixture board to use the opposite select line. Alex-RX test fixture now uses T X select pin Alex-TX test fixture now uses RX select pin This allows use of a standard control cable

13 Alex RX Testing Filter Selection Problem: Mercury selects f ilters based on f requency. - But - For some tests, we wa nt to select the wrong filter on purpose to test the filter s stop-band response We also need to activate relays on the test f ixture board which is masquerading as an opposite -type board Other relays (such as the T /R relay) are directly operated by the PC software

14 Alex RX Testing Filter Selection Solution: Modify the Mercury FPGA f irmware to: Ignore all direct relay commands Set all relays based on the bottom 7 bits of the f requency Beware the decimal to hex conversion!

15 Alex RX Testing Software Problem: There are LOTS of boards to test Do you really want to manually s weep each one? The answer would be NO! Repetitive tasks are best done with? A computer! We re in luck, since we have one or two of those!

16 Alex RX Testing Software Solution: Coerce encourage someone else to write a test program John Melton G0ORX/N6LYT graciously took on the task, and provided us with many revisions and f ixes throughout the testing phase.

17 Alex RX Testing Software Alextest: Separate tests f or RX and TX Allows stepping (f or debug) Allows pause (for 6M trimmer adjustment) Test sequence and timing are directed by a text f ile Color-coded pass/fail results on screen Compiled for Ubuntu Fast execution!

18 Alex Testing Summary Test fixtures built from modified production boards No custom test fixture required Parallel connect -disconnect using BNC F/F, SMB Fast setup with minimal cable connections Custom Mercury FPGA image to select f ilters Flexible approach simplifies test software design Custom software for f ast and repeatable test results Text config file eliminates compiles to change test parameters

19 Alex Testing Summary Color-coded pass/fail results on screen Simple, unambiguous results Compiled for Ubuntu Supported and readily available PC platform Fast execution! Prevents hair loss (too late!)

20 Alexiares RF Bandpass Filters Alex Final Test

21 Alexiares RF Bandpass Filters Alex Final Test, Action Photo!

22 The Moral is? Rooster Sez: Don t let a simple task get your goat!

23 Thank you! Alex Designer: Graham, KE9H Test Software: John, G0ORX/N6LYT Boards available at: