AnsweredAssumed Answered

Frequency doubling sensor setup

Question asked by Cho on Jun 24, 2015
Latest reply on Jul 10, 2015 by s.ilke

Dear Marty,

 

I really appreciated your answers and I would like to discuss my frequency doubling sensor with you more. Although I upload the same issue, it seems that section is closed. (https://ez.analog.com/message/206034#206034)

 

The figure below is the simple concept diagram of my sensor.  The frequency of input signal is 2.9GHz and that of output is 5.8GHz. To turn on or off the sensor, an RF switch is located between the 2.9GHz path antenna and frequency doubling chip. When the switch is off, the 2.9GHz RF signal goes to ground by via. On the other hand, when the switch is on, the 2.9GHz RF signal goes through frequency doubling chip and the sensor is activated. To provide DC voltage, a 2GHz rectenna will be added. If the DC voltage level is not enough, charging pump will be added. So, my intention is that we only want to activate the sensor when we provide the 2GHz RF signal.

 

Herein lies my questions.

Which RF switch model is recommended? (we want low control voltage such as 1V).

Actually, we just need turn on and off. We do not need path switching.

doubler.jpg

 

 

I would like to ask one more question about a reader setup for frequency doubling sensor as the figure below. We would like to use  VNA(due to resource limit) and measure S21. However, since output frequencies are doubled, it is difficult to measure S21 with VNA (PNA). So, I will try to add a frequency divider (divided by 2) between a receiving antenna and Port2 to achieve S21 measurement. In this case, which frequency divider can I use? Could you please let me know a model number?

In addition, do you think I can get S21 measurement in this way? I also considered that power level would be distorted by the frequency divider with some extent.

Picture1.png

 

 

I am looking forward to your valuable opinion.

 

Thanks,

Chunheee

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