Hectoryx
Junior Member level 1
Hi, everyone, I am doing a transceiver system working in 25MHz carrier.
A single electrode was used to be both transmitting antenna and receiving antenna. Apparently, a antenna switch was needed.
The transmit signal was acquired by series LC resonance circuit. As a result, it had a high voltage (approximately more than 50V) and low current.
Initially, I used analog switch IC (ADG749) to implement the antenna switch. Because of the high voltage, it was impossible to let the transmit signal go through ADG749. A solution as in the attached picture was test. In the solution, the transmitter will be shut down when the system worded as a receiver. It works well. However, when the system worded as a transmitter, the transmit signal voltage shrank too much because of the voltage clamp effect of the input pin of ADG749. It cannot be accepted.
I do not know how to resolve this problem. Please help me improve it or suggest a new one. Thanks in advance.
Best Regards.
Hector
A single electrode was used to be both transmitting antenna and receiving antenna. Apparently, a antenna switch was needed.
The transmit signal was acquired by series LC resonance circuit. As a result, it had a high voltage (approximately more than 50V) and low current.
Initially, I used analog switch IC (ADG749) to implement the antenna switch. Because of the high voltage, it was impossible to let the transmit signal go through ADG749. A solution as in the attached picture was test. In the solution, the transmitter will be shut down when the system worded as a receiver. It works well. However, when the system worded as a transmitter, the transmit signal voltage shrank too much because of the voltage clamp effect of the input pin of ADG749. It cannot be accepted.
I do not know how to resolve this problem. Please help me improve it or suggest a new one. Thanks in advance.
Best Regards.
Hector