Circulator-enabled signal suppressor (CENSOR) for reducing co-site transmission interference

A broadband co-site transmission interference suppressor system comprising:

• an antenna;
• a receiver operatively coupled to the antenna;
• and
• a plurality of interference suppressors operatively coupled between the antenna and the receiver, wherein each interference suppressor is designed to operate in different sub-bands of the frequency band of the antenna, and wherein each interference suppressor comprises:
• a) a circulator comprising first, second, and third ports, wherein the first port is disposed to receive an incoming signal from the antenna, wherein the incoming signal comprises a desired signal and an interference signal, and the third port is operatively coupled to the receiver,
• b) a reflective, tunable bandpass filter-bank operatively coupled to the second port, disposed to reflect a reflected signal back into the second port and to produce a filtered signal, wherein the reflected signal comprises the desired signal and a reflected portion of the interference signal, and the filtered signal comprises an un-reflected portion of the interference signal;
• c) a tunable radio frequency (RF) canceller disposed to adjust the amplitude and phase of the filtered signal to create a canceller signal;
• and
• d) a combiner operatively coupled between the third port and the receiver and disposed to combine the reflected signal from the third port with the canceller signal from the RF canceller such that the reflected portion of the interference signal is substantially reduced before the reflected signal reaches the receiver.

A method of suppressing co-site transmission interference comprising the following steps:

• a) receiving at a first port of a three-port circulator an incoming signal comprising a desired signal and an interference signal from a co-sited transmitter;
• b) directing the incoming signal from the second port into a bank of tunable bandpass filters;
• c) reflecting the desired signal and a portion of the interference signal off of the filter-bank back into the second port;
• d) filtering the desired signal out of the incoming signal and outputting the interference signal from the filter-bank;
• e) directing the outputted interference signal from the filter-bank into a radio frequency (RF) canceller;
• f) adjusting the phase and amplitude of the outputted interference signal to create a canceller signal;
• and
• g) directing the reflected desired signal and the portion of the interference signal that exits the third port to a receiver.