Patent ID: 7301419

Claim:
A filtering-type high frequency switching circuit having one input terminal, one output terminal, and a switch circuit connected between the input terminal and the output terminal, a potential of at least one location of the switch circuit being made controllable to pass or cut off a high frequency of a desired bandwidth, the filtering-type frequency switch circuit comprising: a first line having one end electrically connected to the input terminal and the other end connected to a first potential via a first capacitor; a second line forming a pair of coupled lines by being at least partly disposed substantially parallel to the first line, and having one end connected to one end of a first diode, the first diode having its other end connected to a second potential; a third line having one end connected to the other end of the second line and the other end connected to one end of a second diode having as its other end the same pole as the first diode connected to the second potential; a fourth line forming a pair of coupled lines by being at least partly disposed substantially parallel to the third line and having one end electrically connected to the output terminal and the other end connected to a third potential via a second capacitor; and a fifth line having one end connected to a connection point between the second line and the third line and the other end connected to a fourth potential, wherein the first and second capacitors, the first and fourth lines, the second and third lines and the first and second diodes respectively have the same device characteristics to each other, wherein the switch circuit is symmetrical about a connection point among the second line, the third line and the fifth line, and wherein the controllable potential is at least one of the second potential and the fourth potential.