An apparatus includes an impedance matching network, a first switch circuit, and a second switch circuit. The impedance matching network generally comprises a first port, a second port, and a third port. The first switch circuit may be coupled between the first port and a circuit ground potential. The second switch circuit may be coupled between the second port and the circuit ground potential. The impedance matching network generally provides a first impedance value for the first port and for the third port when the second port is connected to the circuit ground potential. The impedance matching network generally provides a second impedance value for the second port and for the third port when the first port is connected to the circuit ground potential. The first impedance value and the second impedance value are asymmetrical.