| 摘要 |
PROBLEM TO BE SOLVED: To enable a calling with satisfactory transmission quality between different radio service areas and further even in the place different in radio wave state within the same radio service area. SOLUTION: This circuit is provided with a local signal level adjusting part 3 and a receiving electric field strength recognizing part 5 and an AMP-AGC 19 controls the size of an intermediate frequency signal Vif according to the size of a level of an input signal. The part 5 detects an operation of a the AMP-AGC 19, changes a voltage level of control voltage Vc and changes forward conductive resistance value of a PIN diode that constitutes the part 3. As a result of that, the size of a local signal V0 is changed and its ratio to an input signal level becomes appropriate. |
