Electronic device for processing radio frequency signals and matching circuit for providing variable impedance

Abstract

An electronic device for processing radio frequency signals includes an antenna, an RF circuit, and a matching circuit. The matching circuit provides variable impedance between the antenna and the RF circuit. The antenna is capable of operating in a first frequency band or a second frequency band according to the variable impedance The matching circuit includes a first element; a second element; a first tuning cell connected to the first element and the second element, and comprising a first tuning element, a second tuning element and a first control element, the first control element determining whether to make a first node connected between the first and second tuning elements couple to a voltage level according to a first control signal; and a selecting circuit coupled to the first control element and configured to generate the first control signal so as to adjust the variable impedance.