High frequency receiving circuit provided with controller for turning on and off power supply to local oscillator

A receiving apparatus comprising a plurality of receiving circuits including first and second receiving circuits, each of said first and second receiving circuits comprising:

• a mixer for mixing an inputted high frequency signal with an inputted local oscillation signal by multiplication to convert the high frequency signal into a predetermined frequency-converted signal, and for outputting the frequency-converted signal;
• a local oscillator for generating a local oscillation signal having a predetermined local oscillation frequency, and for outputting the local oscillation signal;
• a first switch circuit for switching over between first and second cases, said first switch circuit in the first case outputting the local oscillation signal outputted from the local oscillator to said mixer, and outputting the local oscillation signal through the local oscillation signal output terminal, and said first switch circuit in the second case outputting a local oscillation signal inputted through the local oscillation signal input terminal to said mixer;
• and
• a controller for controlling in the first case to turn on power supply to the local oscillator, and controlling the first switch circuit in the first case to output the local oscillation signal outputted from the local oscillator to said mixer, and to output the local oscillation signal through the local oscillation signal output terminal, and for controlling in the second case to turn off power supply to the local oscillator, and controlling the first switch circuit in the second case to output the local oscillation signal inputted through the local oscillation signal input terminal to said mixer,
• wherein the local oscillation signal output terminal of said first receiving circuit is connected to the local oscillation signal input terminal of said second receiving circuit,
• wherein said controller of the first receiving circuit controls the first receiving circuit to turn on power supply to the local oscillator, controls the first switch circuit to output the local oscillation signal outputted from the local oscillator to said mixer, and to output the local oscillation signal to said mixer of the second receiving circuit through the oscillation signal output terminal, and
• wherein said controller of the second receiving circuit controls the second receiving circuit to turn off power supply to the local oscillator, and controls the first switch circuit to and to output the local oscillation signal inputted through the local oscillation signal input terminal to said mixer.

A receiving apparatus comprising a plurality of receiving circuits including first and second receiving circuits, each of said first and second receiving circuits comprising:

• a mixer for mixing an inputted high frequency signal with an inputted local oscillation signal by multiplication to convert the high frequency signal into a predetermined frequency-converted signal, and for outputting the frequency-converted signal;
• a local oscillator for generating a local oscillation signal having a predetermined local oscillation frequency, and for outputting the local oscillation signal;
• a first switch circuit for switching over between first and second cases, said first switch circuit in the first case outputting the local oscillation signal outputted from the local oscillator to said mixer, and outputting the local oscillation signal through the local oscillation signal output terminal, and said first switch circuit in the second case outputting a local oscillation signal inputted through the local oscillation signal input terminal to said mixer;
• a controller for controlling in the first case to turn on power supply to the local oscillator, and controlling the first switch circuit in the first case to output the local oscillation signal outputted from the local oscillator to said mixer, and to output the local oscillation signal through the local oscillation signal output terminal, and for controlling in the second case to turn off power supply to the local oscillator, and controlling the first switch circuit in the second case to output the local oscillation signal inputted through the local oscillation signal input terminal to said mixer;
• a local oscillation signal input and output terminal;
• and
• a second switch circuit for switching over between the first and second cases, said second switch circuit in the first case outputting the local oscillation signal outputted from the local oscillator through the local oscillation signal output terminal and the local oscillation signal input and output terminal, and said second switch circuit in the second case outputting the local oscillation signal inputted through the local oscillation signal input and output terminal to said mixer through the local oscillation signal input terminal and the first switch circuit,
• wherein said controller further controls the second switch circuit in the first case to output the local oscillation signal outputted from the local oscillator through the local oscillation signal output terminal and the local oscillation signal input and output terminal, and controls the second switch circuit in the second case to output the local oscillation signal inputted through the local oscillation signal input and output terminal to said mixer through the local oscillation signal input terminal and the first switch circuit,
• wherein the local oscillation signal input and output terminal of the first receiving circuit is connected to the local oscillation signal input and output terminal of the second receiving circuit,
• wherein said controller of the first receiving circuit controls the first receiving circuit to turn on power supply to the local oscillator, and controls the first and second switch circuits to output the local oscillation signal outputted from the local oscillator to said mixer, and to output the local oscillation signal to said mixer of the second receiving circuit through the local oscillation signal input and output terminal, the second switch circuit and the local oscillation signal input and output terminal,
• wherein said controller of the second receiving circuit controls the second receiving circuit to turn off power supply to local oscillator, and controls the first and second switch circuits to output the local oscillation signal inputted from the first receiving circuit through the local oscillation signal input and output terminal to said mixer through the second switch circuit, the local oscillation signal input terminal and the first switch circuit.