Switch, antenna tuner, and radio frequency apparatus

An antenna tuner, comprising at least two capacitive tuning apparatuses that are connected in parallel, wherein each capacitive tuning apparatus comprises:

• an input end, configured to receive a radio frequency signal;
• a capacitive tuner including a capacitor, configured to tune the radio frequency signal to obtain a tuned signal;
• an output end, configured to output the tuned signal;
• and
• a switch comprising:
• 2N successively serially connected transistors and N is an integer greater than or equal to 2;
• wherein the 2N successively serially connected transistors are divided into groups of odd and even numbered transistors;
• control ends of any two transistors in the odd-numbered group with closest odd sequence numbers are coupled to each other through a first resistor;
• control ends of any two transistors in the even-numbered group with closest even sequence numbers are coupled to each other through a second resistor;
• control ends of n-th and (n+1)-th transistors in the 2N successively serially connected transistors are coupled to a first control signal, and
• wherein n is an integer that is greater than or equal to 1 and is less than or equal to 2N−1, and the first control signal is used to control turn-on or turn-off of the switch
• wherein the switch and the capacitor are serially connected, and the switch, under control of the switch control signal, is capable of selectively coupling the radio frequency signal to the capacitor, so that the radio frequency signal is tuned by using the capacitor.

A radio frequency apparatus, comprising:

• an antenna;
• and
• a tuner;
• wherein the tuner comprises at least two capacitive tuning apparatuses connected in parallel, each capacitive tuning apparatus comprising:
• an input end configured to receive a radio frequency signal, a capacitive tuner configured to tune the radio frequency signal to obtain a tuned signal, and an output end configured to output the tuned signal;
• and
• wherein the capacitive tuner comprises a capacitor configured to tune the radio frequency signal, and
• a switch;
• wherein the switch comprises:
• 2N successively serially connected transistors and wherein N is an integer greater than or equal to 2;
• the 2N successively serially connected transistors are divided into groups of odd and even numbered transistors;
• control ends of any two transistors in the odd-numbered group with closest odd sequence numbers are coupled to each other through a first resistor;
• control ends of any two transistors in the even-numbered group with closest even sequence numbers are coupled to each other through a second resistor;
• control ends of n-th and (n+1)-th transistors in the 2N successively serially connected transistors are coupled to a first control signal, and
• wherein n is an integer that is greater than or equal to 1 and is less than or equal to 2N−1, and the first control signal is used to control turn-on or turn-off of the switch;
• wherein the switch and the capacitor are serially connected, and the switch, under control of the switch control signal, is capable of selectively coupling the radio frequency signal to the capacitor, so that the radio frequency signal is tuned by using the capacitor;
• the antenna is configured to receive the tuned signal from the tuner, and send the tuned signal.