Receiver
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiroaki Ozeki, Hitonobu Furukawa, Masanori Suzuki, Sanae Asayama, Masashi Yasuda
Life of this patent
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Abstract
A receiver is operable even if including a local oscillator generating a signal at high frequencies but not in a wide frequency range. The receiver includes: a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into respective signals of plural first intermediate frequencies corresponding to a frequency of the received signal; and a second frequency converter for converting the signals of the first intermediate frequencies into a signal of a second intermediate frequency.
Claims5
A receiver comprising:
- a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into respective signals of a plurality of first intermediate frequencies corresponding to a frequency of the received signal;
- and
- a second frequency converter for converting the signals of the first intermediate frequencies into a signal of a second intermediate frequency.
A receiver comprising:
- a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into a signal of a first intermediate frequency;
- and
- a second frequency converter for converting the signal of the first intermediate frequency into a signal of a second intermediate frequency,
- wherein the first frequency converter sets a frequency of the first local oscillation signal to one of an upper local oscillation frequency which is higher than the first intermediate frequency and a lower local oscillation frequency which is lower than the first intermediate frequency, and
- wherein a lowest limit of a range of the first local oscillator frequency is higher than a sum of the second intermediate frequency and a highest limit of a frequency range of the received signal.
A receiver apparatus comprising:
- a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into a signal of a first intermediate frequency;
- a second frequency converter for converting the signal of the first intermediate frequency into a signal of a second intermediate frequency;
- a filter coupled between the first and second frequency converter for passing the signal of the first intermediate frequency;
- and
- a switching circuit for deactivating the filter except when an output signal of the first frequency converter contains an interference signal of an image frequency for the second frequency converter.
A receiver apparatus comprising:
- a first frequency converter for mixing a received signal with a first local oscillation signal to convert the received signal into a signal of a first intermediate frequency;
- a second frequency converter including an image rejection type mixer for converting the signal of the first intermediate frequency into a signal of a second intermediate frequency;
- and
- a controller for activating a part of the image rejection type mixer when an output signal of the first frequency converter does not contain a signal of an image frequency for the second frequency converter.
Dependencies are inferred from the claim text.