PicoZed SDR GPOI, Tuning and Workshop Questions

Question

Hello Matt and the PicoZedu2122 SDR Community,

I have a few questions before purchasing a PicoZed SDR Development kit.

I plan on using the PicoZed SDR development kit and the Mathworks tools for prototyping a system requiring fast antenna switching, as low as 200 microseconds between RF switch settings.
1. I thought I would start with the four AD9361 GPO lines on the P3 connector for antenna switch control but ultimately I need more GPIO lines. Can the RF_GPIO lines on the P3 connector be used for antenna and/or RF pre-selector switching?
2. Does anyone know if the J3 AD9361_GPO and RF_GPIO lines are controllable through the Mathworks tools?
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RF tuning and up-converter question:
1. Assuming a 70 MHz lower tune frequency means the pass-band center, is the lowest receivable frequency 70 MHz - 56 MHz/2 = 42 MHz?
2. Is it possible for one of the SDR SOM transmit channels to generate an LO signal so the 2 to 42 MHz band can be up-converted, with external filters/mixers, to fit within the AD9361 receive frequency range?
a. For example, if a combination of RF filters were used to provide an RF pass-band of 2 to 48 MHz (25 MHz center), could an SDR SOM transmit channel generate an LO frequency of 275 MHz to externally mix the 2 to 48 MHz RF pass-band up to a 300 MHz center frequency while the two SDR receiver channels are tuned to 300 MHz and generating samples continuously?
b. I know there are practical issues with getting this to work with good RF performance. I'm just wondering if the SDR SOM will support receiving on both channels while using one transmit channel as an LO for an external block up-converter.
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Are there any thoughts of having a PicoZedu2122 SDR Speedway Design Workshop in Northern California?

Thanks for Your Help,
Steve

mbrown · Accepted Answer

Hello Steve,

Regarding the MathWorks questions, yes you can control the AD9361_GPO.

1) Simulate your design, including the AD9361 model as part of your overall Simulink design. (Golden Model)

2) Modify the Simulink design as needed to prepare for code generation. (Codegen Model)

3) Use the HSP to generate code and execute on the target. Simulink sends AD9361 configuration data to PicoZed SDR over Ethernet and the Zynq SoC in turn programs the AD9361 via SPI interface on Zynq.

The AGC/gain tables in the AD9361 control the AD9361 GPO, therefore by configuring the AD9361 Simulink model, those GPO signals can be controlled. With an AD-PZSDR2400TDD-EB RF Personality module connected to P3 of the FMC Carrier, you could control the LNA, however the AD9361 model is set to FDD mode, so control of the RX/TX switch is not enabled.

Any other signals you'd like to control would require a change in the Hardware Support Package for PicoZed SDR, which is entirely possible with their extensible API.

Regarding the RF questions, the PicoZed SDR module supports everything the AD9361 supports. Your best bet for specific questions on configurations of the AD9361 would be the ADI EngineerZone (ez.analog.com).

Thanks,

Matt