Transponder stabilization

A method for reflection of an incident wave, the method comprising:

• generating a first input signal at a third port of a hybrid coupler by receiving the incident wave using a first antenna;
• generating a second input signal at a fourth port of the hybrid coupler, the second signal being essentially 90 degrees shifted with respect to the first signal;
• inputting the first input signal and the second input signal to the hybrid coupler thereby generating a first output signal at a first port of the hybrid coupler, said first output signal being a destructive combination of the first input signal and the second input signal;
• and generating a second output signal at a second port of the hybrid coupler, said second output signal being a constructive combination of the first input signal and the second input signal;
• absorbing at least substantially the first output signal using a termination unit connected at the first output port;
• amplifying the second output signal using the negative resistance amplifier for generating an amplified signal, and then feeding the amplified signal to the second port of the hybrid for generating a first transmitted signal at the third port of the hybrid;
• reflecting a first reflected wave proportional to the first transmitted signal using the first antenna element;
• and
• receiving any non-desired signals, generated due to non-idealities such as mismatch, at the first port and absorbing at least substantially said non-desired signals using the termination unit.