| 摘要 |
PURPOSE:To reduce a device at its size without additionally preparing an element to supply bias current to a switching diode by turning on and off a transmission/reception switching diode by collector current from the oscillation stage of a transmitter. CONSTITUTION:When a high frequency signal is inputted from an oscillator OSC, an amplifying transistor TR1 is turned on, the collector current is made flow through a coil RF4, switching diodes D2, D3 and TR1 and the diodes D2, D3 are turned on. The high frequency signal amplified by TR1 drives TR2 through a network 2 and is guided to an antenna terminal ANT through the diode D2 turned on after amplification. When a high frequency signal is inputted from the oscillator OSC to TR1, the diodes D2, D3 are turned off and a receiving signal from the ANT terminal is guided to a receiving terminal (REC). |
