RADIO FREQUENCY FRONT END ARCHITECTURE WITH A SWITCH TOPOLOGY FOR ROUTING FILTER CIRCUITS WHILE SUBSTANTIALLY REDUCING VARIATIONS IN THE REACTIVE LOADING AT COMMON PORTS

摘要

Radio frequency (RF) front end circuitry is disclosed that includes a filter circuit, a first switch device, and a second switch device. The filter circuit is coupled to present a filter capacitance to the first RF port and to the second RF port. The second switch device is configured to present a device capacitance to the second RF port when a common port of the second switch device is shunted to ground. The first switch device is configured to present approximately the filter capacitance and the device capacitance to its common port. The device capacitance from the second switch device can thus be used to tune a total capacitance presented to the common port of the first switch device. As such, the total capacitance presented to the common port of the first switch device can be maintained substantially unchanged without requiring a substantial increase in the number of switching components.

主权项

1. Radio frequency (RF) front end circuitry comprising:
a first filter circuit having a first filter capacitance wherein the first filter circuit is coupled to present the first filter capacitance to a first RF port and to a second RF port, wherein the first RF port and the second RF port are coupled to one another; a first switch device comprising a first common port, the first RF port, a first switchable series path connected in series between the first common port and the first RF port, and a first switchable shunt path connected in shunt with respect to the first common port wherein the first switch device is configured to present approximately the first filter capacitance and a first device capacitance from the first RF port to the first common port when the first switchable series path is closed and the first switchable shunt path is opened; and a second switch device comprising a second common port, the second RF port, a second switchable series path connected in series between the second common port, and a second switchable shunt path connected in shunt with respect to the second common port wherein the second switch device is configured to present the first device capacitance to the second RF port when the second switchable series path is opened and the second switchable shunt path is closed.