Radio frequency front end for fdd-tdd carrier aggregation systems and methods

Abstract

Radio-frequency front end circuitry systems and methods for carrier aggregation include multiple RF signal paths, switching circuitry, and timing control circuitry. The switching circuitry is configured to selectively couple the RF signal paths to an antenna port and includes, for each RF signal path, a thru switch connecting a corresponding RF signal path to the antenna port when activated, and a shunt switch connected between its corresponding signal path and RF ground. The timing control circuitry for each TDD path may include a thru control signal path connecting a control signal to the thru switch and a shunt control signal path with at least one delay element to delay the shunt control signal. The timing control circuitry may include delay elements, a resistor-capacitor circuit and a Schmitt trigger. The timing control circuitry may include a non-overlap circuit for each TDD path to mitigate overlap in switching operations.