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Various Power Measurements in AD9361 Rx Chain

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I am interested in clarifying the following three "different" power measurement in the AD9361 RX chain:

 

1. Dec power measurement in Fast AGC stage 2 and 3.

2. Power measurement in Fast AGC stage 5.

3. RSSI power measurement.

 

Based on descriptions in UG-570 and UG-671, I drew the following four conclusions. 

 

Conclusion A: Because each of the three above power measurements has its own configurable measurement length,  they are independent measurements, not relying on each other in calculation, and are implemented separately in the circuit. 

 

Conclusion B: Register 0x15C is only used for the Dec Power measurement in Fast AGC stage 2 and 3, including choosing whether using HB1 output or RFIR output. It only effects Fast AGC stage 2 and 3. Note in UG-671, [D6] is specifically named as "Use HB1 Out for Dec Pwr Meas".

 

Conclusion C: RSSI power measurement ALWAYS uses the RFIR output, even if RFIR is bypassed. Although Reg0x15C is put in the RSSI section in UG-671, it has nothing to do with RSSI power measurement.

 

Conclusion D: Power measurement in Fast AGC stage 5 ALWAYS uses HB1 output. This measurement point is not configurable.

 

Please review and correct me if any of the above conclusions are wrong. Thanks!


DEMO-AD5700D2Z HART_CLK connection

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Hi,

 

This is regarding DEMO-AD5700D2Z board. I just started programming and evaluate the performance of the ICs in-order to zero in on them. I see that HART_CLK is connected to both P2.0 and P1.0. Can someone please explain me what is the reason to connect to two pins?

Also, on a custom board, I want to connect HART_CLK to just P1.0 as I want to use P2.0 and P2.1 as I2C lines. Is it feasible?

 

Thanks,

Spoorthy

 

ad5700 ad5700-1 hartdemo-ad5700d2z

Can AD9361 be designed as a notch filter?

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If it can ,can you provide some specific methods?Thank you

AD9361 Register 0x137 D4:D3?

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According to UG-671, [D4:D3] of AD9361 Register 0x137 is used for receiver selection. Specifically, D3 for Rx1 and D4 for Rx2. And, as said in UG-671, "When reading the table, setting both bits is invalid". What does this mean? Is there two separate instance of tables, one for each receiver?

Custom dual AD9361 Board LVDS path lengths.

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I don't see it implicitly stated any where but is it important that the LVDS interface trace lengths are the same length from the FPGA to both AD9361s?

 

I know in the HDL the l_clk is tied from core 0 to the clk input of core 0 and 1.

 

I am aware that the data sheet says that the 40 MHz buffered clk trace lengths should be the same.

 

If the traces cannot be made the same, how can I account for this on the HDL - No-OS side? I would be okay with loosing the ability for chip to chip synchronization as long as I can still get synced 1RX2RX from each chip.

More details about AD9361 DC correction & tracking

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Hello,

 

We are optimizing the register settings for both RF & BB DC tracking and correction. There seems to be quite many parameters to adjusts and the manual UG-570 provides in our opinion too few details to fully understand the settings in UG-672 (register map). To better understand all settings, are there any documentation available with for example block diagrams explaining the DC correction & tracking?

 

Kind regards,

Timo

ADuCM302x Example code without drivers

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Do you have basic example code for each of the peripherals on the ADuCM302x that does not require the drivers?

Thanks!

ask for dsp question?


ADL5304 Output Slowly Ramps Up When Light is Blocked on Photodiode Input

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My question is about the ADL5304 Log Amplifier.

 

I used this Log Amp on a board design and in general it works fine.  I am able to get 8 decades of dynamic range (outstanding!).  The input to this Log Amp is a photodiode, an EPM705, similar or identical to the one that is used in the Application Section of the ADL5304 data sheet.

 

However, I observe that with no light on the photodiode,  the output of the log amplifer slowly ramps up to about 2 volts.  I am very careful to make sure there is absolutely no light on the photodiode.

 

Is this due to leakage current in the photodiode?  I know that the ADL5304 has "Adaptive Bias Current" control, and I exploited that feature in my design. 

 

I have attached the schematic here.

AD9361 test

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Hi,

 

I am working on a picozed sdr2 rev. e. I am trying to verify the performance of the ad9361 by doing the test measurement for 2.4GHz for the transmit chain based on the page 4 of the datasheet as attached. I will like to clarify on that page under the test case for transmitter 2.4GHz .The measurement was tested based on 1MHz tone as stated on the test condition column.

 

Here comes my questions:

1) The 1 MHz is generated from the dds , am I right? If it is, what is the scale set to in the OS driver and at the non-OS driver.

2) For the maximum power obtained, how you get that high reading? By setting the Tx attenuation to 0dB? From the NON-OS driver and OS driver, I could not find any setting to increase the Tx gain other than by reducing the Tx attenuation.

3) For the modulation accuracy(EVM) , how did you capture the measurement? From what I know EVM is known as error vector magnitude which is used to determine the error offset of your IQ sample positioned on the constellation diagram and is determine in %, but according to the datasheet, the unit is in dB. So what is the EVM that you all are referring to ? I am using MXA Signal Analyser N9020A for my measurement

4)For the carrier leakage, there are 2 readings, is it aligned to the test condition by setting the Tx attenuation to 0 dB , a carrier leakage  will be observed at -50dBc , and also by setting the Tx attenuation to 40 dB , carrier leakage  will be observed at -32dBc . Am I right?

5) The noise floor at -156dBm/Hz is due to the 90MHz offset . What question is that what is this 90MHz offset about? How does it affect the noise floor and this offset is generated from where? How do I even set it?

6) Regarding the Isolation part , what is the isolation about , what do you mean by TX1 to TX2 : 50 dB ?

7) For the test case if I set TX LO to 800MHz, I realise that the clk ref used is 19.2MHz. From what is know for Picozed SDR2 , it is using a onboard 40MHz crystal . So if I need to verify the 800Mhz test speciation as refer on the datasheet , I will need to inject an external 19.2MHz clk rate in? Am I right? Is there any reason why the clk rate used for 800Mhz is different from 2.4GHz and 5.5Ghz test case?

 

The reason I am asking this is because I realise there is a some performance difference between the OS-driver and  NON-OS driver approach. Now due to my application, I will require to inject an external clk rate in as well. So because moving forward to my application, I must be sure that the test specification is as per stated in the datasheet for both OS and NON-OS approach (This might determine which approach I will move forward w.r.t the performance observed).

AD9361 Test Specification

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Hi,

 

I am working on a picozed sdr2 rev. e. I am trying to verify the performance of the ad9361 by doing the test measurement for 2.4GHz for the transmit chain based on the page 4 of the datasheet as attached. I will like to clarify on that page under the test case for transmitter 2.4GHz .The measurement was tested based on 1MHz tone as stated on the test condition column.

 

Here comes my questions:

1) The 1 MHz is generated from the dds , am I right? If it is, what is the scale set to in the OS driver and at the non-OS driver.

2) For the maximum power obtained, how you get that high reading? By setting the Tx attenuation to 0dB? From the NON-OS driver and OS driver, I could not find any setting to increase the Tx gain other than by reducing the Tx attenuation.

3) For the modulation accuracy(EVM) , how did you capture the measurement? From what I know EVM is known as error vector magnitude which is used to determine the error offset of your IQ sample positioned on the constellation diagram and is determine in %, but according to the datasheet, the unit is in dB. So what is the EVM that you all are referring to ? I am using MXA Signal Analyser N9020A for my measurement

4)For the carrier leakage, there are 2 readings, is it aligned to the test condition by setting the Tx attenuation to 0 dB , a carrier leakage  will be observed at -50dBc , and also by setting the Tx attenuation to 40 dB , carrier leakage  will be observed at -32dBc . Am I right?

5) The noise floor at -156dBm/Hz is due to the 90MHz offset . What question is that what is this 90MHz offset about? How does it affect the noise floor and this offset is generated from where? How do I even set it?

6) Regarding the Isolation part , what is the isolation about , what do you mean by TX1 to TX2 : 50 dB ?

7) For the test case if I set TX LO to 800MHz, I realise that the clk ref used is 19.2MHz. From what is know for Picozed SDR2 , it is using a onboard 40MHz crystal . So if I need to verify the 800Mhz test speciation as refer on the datasheet , I will need to inject an external 19.2MHz clk rate in? Am I right? Is there any reason why the clk rate used for 800Mhz is different from 2.4GHz and 5.5Ghz test case?

 

The reason I am asking this is because I realise there is a some performance difference between the OS-driver and  NON-OS driver approach. Now due to my application, I will require to inject an external clk rate in as well. So because moving forward to my application, I must be sure that the test specification is as per stated in the datasheet for both OS and NON-OS approach (This might determine which approach I will move forward w.r.t the performance observed).

How do I simulate AD9833?

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Hello,

 

I want to simulate with AD9833. So i need any simulation software. Please let me know is there any Simulation Software that contain AD9833 IC.

 

Thanks and regards

Thippeswamy

Indoor positioning system

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I am looking for a single chip UWB transceiver, which can be used as part of an indoor positioning system for a virtual reality arcade. However, I have not been able to find a single chip solution on your website. I have come across the AD9361 and since I am comfortable with FPGAs and the digital side of SDRs my question follows.

 

What other components would I require to implement an UWB transceiver, using the AD9361/AD9364 and a FPGA? If you could provide a high-level block diagram of the relevant parts, then this would be even more helpful.

 

Thanks in advance.

AD9361 image interference and harmonic interference

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I use the DDS to produce all the 1MHz cos and a sin signal through the digital data interface in the CMOS mode passed to the AD9361, AD9361 launch of the local oscillator frequency is 2290MHz, in the spectrum analyzer to see the mirror is not suppressed, and harmonic Interference is very serious, but the use of 9361 internal BIST register to see the launch part of the suppression is very good, I do not know what the reason is the timing of the interface problems or register configuration problems? The drawings are mirrors and harmonics seen on the spectrum analyzer.

我用DDS产生均为1MHz的一路cos和一路sin信号通过数字数据接口在CMOS模式下传给AD9361,AD9361发射的本振频率是2290MHz,在频谱仪上看到镜像完全没有被抑制,且谐波干扰很严重,但是使用9361内部的BIST寄存器查看发射部分抑制的很好,不知是什么原因,是接口的时序有问题还是寄存器配置有问题?附图是频谱仪上看到的镜像和谐波。

AD9364 RX/TX path delays

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I am using no-os driver to configure an AD9364.

 

I have set the RX and TX sample rates to 60MHz.  This results in the following clock chain:

ad9361_set_trx_clock_chain: 960000000 480000000 240000000 120000000 60000000 60000000
ad9361_set_trx_clock_chain: 960000000 240000000 120000000 60000000 60000000 60000000

 

Both rx and tx FIR are disabled.

 

Looking at the AD9364 users guide "DIGITAL Rx BLOCK DELAY" it looks like I should be seeing a delay contribution from the digital filters of approx:

                  HB3           HB2           HB1    

RX path (2/240M) + (2/120M) + (7/60M) = 8.3ns + 16.6ns + 116ns = 140ns

TX path (2/120M) + (2/60M)  + 0             = 16.6ns + 33.8ns             =  50.4ns

 

= 190.4ns total delay for digital filters

 

I am using an ILA in Vivado to capture the TX and RX data just before clocking in/out to the AD9364.  I am seeing a delay of approx. 800ns.

 

I know that the 190ns is only the digital filter delay.  Is there a description somewhere of what the source migth be for the additional ~600ns delay I am measuring


AD9361 No-Os Driver TDD Pin Pulse Mode

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Hello. I am using the AD9361 and had a functioning design with both RX and TX in FDD mode. I am trying to switch the design to TDD pin pulse mode by doing the following in the NO-OS driver:

 

Set "//frequency_division_duplex_mode_enable *** adi,frequency-division-duplex-mode-enable" from 1 to 0

Set both "//ensm_enable_pin_pulse_mode_enable *** adi,ensm-enable-pin-pulse-mode-enable" and 

"//ensm_enable_txnrx_control_enable *** adi,ensm-enable-txnrx-control-enable" from 0 to 1

 

I implemented signals generated on both the ENABLE and TXNRX pins according to the UG-570 AD9361 Reference Manual Figure 10: Enable Pulse Mode, TDD. I have probed the test points on the FMCOMMS2 board and they are behaving identically as the diagram shows. However, I am no longer seeing and TX data. Is there another setting init_param that I need to change to allow TDD mode to work? Or is there a minimum time needed in the alert state other than the ~6 clock cycles depicted in the figure?

Capturing data from ADS7-V2EBZ

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Hello,

 

Recently ADI has released  a new ADC : AD6688 . When I use AD6688-3000EBZ with ADS7-V2EBZ, I can not to capture data from ACE on PC. And I have operate according  to  "EVALUATING THE AD6688 RF DIVERSITY and 1.2 GHz BANDWIDTH OBSERVATION RECEIVER".   The SPI communication is successful and  the PLL Locked indicator  light is green. Soon  afterwards  I  find   the lights of S5 and S6  go off on ADS7-V2EBZ .Why?  And how can I do?

 

 

Thanks,

Ping

AD9361 IIO Oscilloscope noise floor

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Hello,

 

In this configuration:

I see this spectrum:

This measure was made on the PicoZed SDR 2x2 SOM. There was no signal at the input.

Why is there more noise around -Fs/2 and +Fs/2?

 

Best regards,

 

Vincent

Does AD9361 support analog RX & TX IQ interfaces or only digital?

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I'd like to know if it is at all possible to bypass the ADCs and DACs on AD9361 and use analog IQ signal interfaces ?

AD9361 RSSI/AGC strange behavior

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Hello.  We are seeing strange AGC/RSSI behavior with an adjacent channel interferer.   Our sample rate is 16MHz and we have a 14MHz bandwidth.  If we inject a large interferer (using CW for now) close to our intended signal (with 70MHz) we see that the RSSI increases as expected (interferer adds to our signal and AGC tracks with less gain).

 

However, when the interefer is farther away from Fc, we see the RSSI drop around 20dB and the AGC is reporting adding more gain.  The interferer is now causing our intended signal to look weaker that what is actually coming in.

 

Has anyone else seen this?  Any ideas of what may be causing it?  Seems like it could be some kind of mixing artifact that could be overflowing one of the AGC calc points.

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