how to store data from DC890B evaluation board into PC in excel format using Pscope software

You can use the recommended Mini-Circuits 180-degree combiners (ZFSCJ-2-1) to convert the differential I+ I- (or Q+ Q-) to single-ended. The DC blocks are required because the LTC5584 has about 3.5V common-mode output voltage. The ZFSCJ-2-1 combiner has internal DC ground connections at its input/output ports. Therefore if you DC-couple the outputs directly to the ZFSCJ-2-1, you would be shorting the 3.5V Vcm to ground. If connectorized DC blocks are not available, you can simply add a large-value series capacitor at each output on the demo board.

sir I want to replace IQ LTC5584 to AD8302(phase detector) and this phase detector connect to DC1945A evaluation board to acquire the digital data, is it possible? can I replace IQ demodulator to phase detector?

Please take a look at the AD8302 product page:

https://www.analog.com/en/products/ad8302.html#product-overview

There are two available evaluation boards: one has analog outputs that you can input to DC1945A, and another board is an Arduino shield with software GUI.

sir, I can't find details evaluation board with DC1945A if any details with same then please provide me.

how to increase analog input range of DC1945A because in the datasheet of DC1945A give analog input range from 62mV to 125mv and AD8302 output voltage range is 0v to 1.8V.

Please order the Arduino shield board and use Arduino instead:

https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-AD8302-ARDZ.html#eb-overview

sir, I have already purchased the DC890B board and I want to acquire the voltage of AD8302 which is 0v to 1.8V so please suggested any ADC board with compatible or supportable to DC890B. please suggested anyone ADC board which supports the analog input range from 0v to 1.8V.thank you

Please see DC890B page -> Related Hardware -> Daughter Boards for compatible ADC demo boards:

https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/dc890b.html#eb-relatedhardware

One of the DC851A family boards may suite your requirement. You can find a list of board versions, ADC part numbers, resolutions, sampling rates, and input frequencies in the DC851A manual:

https://www.analog.com/media/en/dsp-documentation/evaluation-kit-manuals/dc851A_A-X.pdf

Thank you for your kind reply,
I had referred the data sheet of demo board DC851A_A-X, contains ADC with the speed from 10 MSPS to 105 MSPS (LTC2280-LTC2299). In all the ADC, the input voltage range is 1VP-P to 2VP-P. While in our application, we want to use a demo board after AD8302 whose output voltage is 0 to 1.9 V.
I am still confused whether it will take the input voltage varying from 0 to 1.9 V or not ??

Thank you for your kind reply,
I had referred the data sheet of demo board DC851A_A-X, contains ADC with the speed from 10 MSPS to 105 MSPS (LTC2280-LTC2299). In all the ADC, the input voltage range is 1VP-P to 2VP-P. While in our application, we want to use a demo board after AD8302 whose output voltage is 0 to 1.9 V.
I am still confused whether it will take the input voltage varying from 0 to 1.9 V or not ??

0 to 1.9V is 1.9Vp-p.