Plural band, single/double conversion radio receiver
AssigneeSony Corporation
InventorMasami Yanagibori
Life of this patent
Estimating the term…
Abstract
In a radio receiver having first and second mixers and in which, during short wave reception, an intermediate frequency signal is produced through the first and second mixers and, during medium wave reception, an intermediate frequency signal is produced through only the second mixer; the second mixer is formed of a pair of transistors having collectors connected to each other and emitters also connected to each other. By changing over switches, the base of one of the transistors is supplied with a received signal during short wave reception, and the base of the other transistor is supplied with a received signal during medium wave reception. As a result, suitable intermediate frequency signals can be selectively obtained at the collectors of the transistors.
Claims7
A radio receiver for selectively receiving broadcast signals in first and second frequency bands, comprising:
- first and second local oscillators for producing respective local oscillation signals;
- a first tuning circuit for tuning to a broadcast signal in said first frequency band;
- a first mixer coupled to said first tuning circuit for converting the broadcast signal of said first frequency band into a first intermediate frequency signal with a local oscillation signal from said first local oscillator;
- a second tuning circuit for tuning to a broadcast signal in said second frequency band;
- a second mixer consisting of first and second transistors each having input, output and common electrodes, said common electrodes of said first and second transistors being connected to each other, and said output electrodes of said first and second transistors being connected to each other;
- means coupling the input electrode of said first transistor to said first mixer for converting said first intermediate frequency signal into a second intermediate frequency signal with a local oscillation signal from said second local oscillator;
- means coupling the input electrode of said second transistor to said second tuning circuit and said first local oscillator for converting the broadcast signal of said second frequency band into an intermediate frequency signal by means of a local oscillation signal from said first local oscillator;
- and
- switching means for selectively enabling and disabling said first and second transistors and thereby providing a respective predetermined intermediate frequency signal at the output electrodes of said transistors corresponding to a broadcast signal selectively received in one of said frequency bands.
Dependencies are inferred from the claim text.