Simultaneous transmission and reception

Hi,

I have successfully tested simultaneous signal transmission and reception in FDD mode, and it works as expected. However, we do not recommend using the same frequency for both transmission (Tx) and reception (Rx) in FDD mode due to potential interference between the Tx and Rx signals. For example:

1. Overpowering the Received Signal: Transmitted signals are typically much stronger than incoming signals. Using the same frequency for Tx and Rx can overwhelm the receiver, effectively drowning out incoming signals and preventing proper reception.

2. Duplexer Limitations: Duplexers, which are designed to isolate transmit and receive signals, cannot achieve perfect isolation on the same frequency. Some transmitted signal may leak into the receiver, leading to interference and degraded performance.

Regards

Rahul 

Hey,

What i am interested in is, will there be any issues within the IC like VCO pulling, improper isolation between the Rx and Tx channel within the IC and possible EM interference between RX and TX line in the PCB etc and I don't plan on transmitting the signal through an antenna.

Hi,

I am interested to know if its possible to have Tx and Rx enabled simultaneously but in a TDD application.

The Tx channel will be briefly enabled to send a short burst of data, then it can be disabled to reduce noise coupling. So that we can process the response  immediately, we would like to keep the Rx on and monitor the data stream.

I accept that the Rx may briefly be saturated by leakage of the Tx signal through the duplexer. We would include protection to avoid damage.

We expect that we may need to use an external RF oscillator instead of internal VCO. Would this mitigate risk of VCO pulling?