Radio receiver, radio communication system and electronic equipment
First Claim
1. A radio receiver, comprising:
- a first down-converter for down-converting a received radio signal to produce an intermediate frequency multiple signal; and
a second down-converter for down-converting the intermediate frequency multiple signal to produce an input signal, whereinthe second down-converter has;
a first path;
a second path;
a divider for dividing the intermediate frequency multiple signal into signals going to the first path and the second path; and
a mixer section,the first path transmits the intermediate frequency multiple signal from the divider to the mixer section,the second path has a filter for extracting a reference signal from the intermediate frequency multiple signal and transmits the reference signal to the mixer section, andthe mixer section multiplies the intermediate frequency multiple signal from the first path by the reference signal from the second path so as to perform frequency down-conversion of the intermediate frequency multiple signal.
1 Assignment
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Accused Products
Abstract
According to the radio receiver, a first path P1 included in a frequency conversion circuit 12 does not have a filter, and a filter 171 for extracting a reference signal 74c is provided in a second path P2 so that a second IF multiple signal 74 and the reference signal 74c are multiplied together in a mixer section 12a. Consequently, by extracting the reference signal 74c, the filter 171 in the second path P2 operates as a local oscillation signal source synchronized with the second IF multiple signal 74. Therefore, according to the signal obtained by down-conversion of the second IF multiple signal 74 with use of the reference signal 74c in the mixer section 12a, signals identical in quality to input signals inputted on the transmission side can be reproduced.
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Citations
23 Claims
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1. A radio receiver, comprising:
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a first down-converter for down-converting a received radio signal to produce an intermediate frequency multiple signal; and a second down-converter for down-converting the intermediate frequency multiple signal to produce an input signal, wherein the second down-converter has; a first path; a second path; a divider for dividing the intermediate frequency multiple signal into signals going to the first path and the second path; and a mixer section, the first path transmits the intermediate frequency multiple signal from the divider to the mixer section, the second path has a filter for extracting a reference signal from the intermediate frequency multiple signal and transmits the reference signal to the mixer section, and the mixer section multiplies the intermediate frequency multiple signal from the first path by the reference signal from the second path so as to perform frequency down-conversion of the intermediate frequency multiple signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A radio receiver, comprising:
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a first down-converter for down-converting a received radio signal to produce an intermediate frequency multiple signal; and a second down-converter for down-converting the intermediate frequency multiple signal to produce an input signal, wherein the second down-converter has; first to fifth paths; an undesired wave removal filter for filtering out undesired waves from the intermediate frequency multiple signal; and a first divider for dividing the intermediate frequency multiple signal into signals going to the first path, the second path and the third path, the first path has a first path filter and a first mixer section, the second path has a reference signal extraction filter for extracting a reference signal from the intermediate frequency multiple signal and a second divider for dividing the reference signal into signals going to the fourth path and the fifth path, the third path has a third path filter and a second mixer section, the fourth path has a first amplifier and transmits the reference signal to the first mixer section, the fifth path has a second amplifier and transmits the reference signal to the second mixer section, the first mixer section multiplies the intermediate frequency multiple signal from the first path by the reference signal from the fourth path so as to perform frequency down-conversion of the intermediate frequency multiple signal, and the second mixer section multiplies the intermediate frequency multiple signal from the third path by the reference signal from the fifth path so as to perform frequency down-conversion of the intermediate frequency multiple signal. - View Dependent Claims (21, 22)
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23. A radio receiver, comprising:
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a first down-converter for down-converting a received radio signal to produce an intermediate frequency multiple signal; and a second down-converter for down-converting the intermediate frequency multiple signal to produce an input signal, wherein the second down-converter; extracts a reference signal from the intermediate frequency multiple signal; and multiplies the intermediate frequency multiple signal containing the reference signal by the reference signal to down-covert the intermediate frequency multiple signal.
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Specification