| 摘要 |
PURPOSE:To use the local oscillator in common to the reception waves of two systems to simplify the constitution of the device as well as to solve the problem of the step-out, by branching off the output of one local oscillator into two parts and carrying out the frequency multiplication after making the branched output pass through the phase shifter featuring a small variable phase shift amount. CONSTITUTION:The reception waves of two systems are compounded with each corresponding local signal to obtain the two-system IF signals, and both signals are compounded together. In the phase shifter of such diversity system, the output of local oscillator 8 is divided into two and one of the branched output is supplied to phase shifter 14. Phase shifter 14 is constituted so that it may produce small phase shift amount less than 360 deg. according to the output voltage of phase detector 17, and the output signal is applied to first multiplying circuit 16. Then the output of circuit 16 is applied to frequency converter 4. The other side of the branched output is applied to second multiplying circuit 15, and the output is applied to frequency converter 3 after n-multiplication. The frequency conversion is given to the received two-system signals against the oscillation wave of local oscillator 8 to obtain the IF signal, and then the received two-system signals are compounded through compound circuit 7. |
