High isolation power combiner/splitter and coupler

A coupler comprising:

• a mutual inductance coupler including—
• an input port
• an output port;
• a coupled port;
• an isolation port;
• a first inductor connected between the input port and the output port;
• a second inductor connected between the coupled and the isolation port;
• a third inductor magnetically coupled to the first inductor and connected between a ground potential and to isolation port;
• and
• a fourth inductor magnetically coupled to the second inductor and connected between the ground potential and to the output port;
• and
• a lossy circuit connected between the input port and the isolation port and having a resistance effective to receive an input signal from the input port and in response to the input signal output a first signal to the isolation port;
• wherein the mutual inductance coupler is effective to receive the input signal from the input port and in response to the input signal output a second signal to the isolation port, the second signal having approximately equal amplitude and opposite phase to the first signal.