Transmission circuit and signal transmission and reception circuit

A transmission circuit comprising:

• a first terminal for inputting or outputting signals;
• a pair of second terminals for outputting or inputting the signals;
• a first path that connects the first terminal and one of the pair of second terminals;
• a second path that connects the first terminal and another one of the pair of second terminals;
• a first circuit including a first capacitor that is serially inserted in the first path, the first capacitor being inserted between the first terminal and the one of the pair of second terminals, the first circuit being configured to perform single-differential conversion on signals transmitted through the first path, and to perform impedance matching;
• a second circuit including a first inductor that is serially inserted in the second path, the first inductor being inserted between the first terminal and the other one of the pair of second terminals, the second circuit being configured to perform single-differential conversion on signals transmitted through the second path, and to perform impedance matching;
• and
• a switch that is connected between the one of the pair of second terminals and the other one of the pair of second terminals,
• wherein
• the first circuit includes:
• the first capacitor,
• a first branch path that branches from between the first capacitor and the one of the pair of second terminals, and that is connected to a reference potential point, and
• a first parallel circuit that is serially inserted in the first branch path, the first parallel circuit including a second inductor and a second capacitor, and wherein
• the second circuit includes:
• the first inductor,
• a second branch path that branches from between the first inductor and the other one of the pair of second terminals, and that is connected to the reference potential point, and
• a second parallel circuit that is serially inserted in the second branch path, the second parallel circuit including a third inductor and a third capacitor.

A transmission circuit comprising:

• a first path that connects a first terminal for inputting or outputting signals, and one of a pair of second terminals for outputting or inputting the signals;
• a second path that connects the first terminal and another one of the pair of second terminals;
• a first capacitor that is serially inserted in the first path;
• a first inductor that is serially inserted in the second path;
• a first branch path that branches from between the first capacitor of the first path and the one of the pair of second terminals, and that is connected to a reference potential point;
• a first parallel circuit that is serially inserted in the first branch path, the first parallel circuit including a second inductor and a second capacitor;
• a first DC power source that is serially inserted in the first branch path, between the first parallel circuit and the reference potential point;
• a second branch path that branches from between the first inductor of the second path and the other one of the pair of second terminals, and that is connected to the reference potential point;
• a second parallel circuit that is serially inserted in the second branch path, the second parallel circuit including a third inductor and a third capacitor;
• a second DC power source that is serially inserted in the second branch path, between the second parallel circuit and the reference potential point;
• and
• a switch that is connected between the one of the pair of second terminals and the other one of the pair of second terminals.