Receiver circuit and radio communication terminal apparatus
First Claim
1. A reception circuit comprising:
- a low noise amplifier having a low noise amplifying circuit with a low gain and a low noise amplifying circuit with a high gain which are capable of selective operation in accordance with control of a bias current; and
a quadrature demodulator connected with a serial capacitance to an output of said low noise amplifying circuit with the high gain of said low noise amplifier and directly connected to an output of said low noise amplifying circuit with the low gain.
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Accused Products
Abstract
There are provided, as a low noise amplifier (70) a low noise amplifier (71) with a low gain and a low noise amplifier (72) with a high gain, selectively operable under control of a bias current, and an output from the low noise amplifier (72) and a quadrature demodulator (80) are connected with a serial capacitance (73) and also an output from the low noise amplifier (71) and the quadrature demodulator (80) are serially connected. A control section (66) controls a reception circuit so that the low noise amplifier (71) operates when a reception signal level is high and the low noise amplifier (72) operates when the reception signal level is low. When the low noise amplifier (72) operates, a DC bias current thereof is made flow separately from a DC bias current of the quadrature demodulator (80), and, when the low noise amplifier (71) operates, a DC bias current thereof is shared with the quadrature demodulator.
60 Citations
12 Claims
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1. A reception circuit comprising:
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a low noise amplifier having a low noise amplifying circuit with a low gain and a low noise amplifying circuit with a high gain which are capable of selective operation in accordance with control of a bias current; and a quadrature demodulator connected with a serial capacitance to an output of said low noise amplifying circuit with the high gain of said low noise amplifier and directly connected to an output of said low noise amplifying circuit with the low gain. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A wireless communication terminal apparatus comprising:
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a low noise amplifier having a low noise amplifying circuit with a low gain and a low noise amplifying circuit with a high gain which are capable of selective operation in accordance with control of a bias current; a quadrature demodulator connected with a serial capacitance to an output of said low noise amplifying circuit with the high gain of said low noise amplifier and directly connected to an output of said low noise amplifying circuit with the low gain; reception level detecting means for detecting a level of a reception signal; and control means for performing control of said reception circuit in accordance with an output of said reception level detecting means, characterized in that; said control means controls said low noise amplifier such that it operates the low noise amplifying circuit with the low gain when said reception signal level is high, and operates the low noise amplifying circuit with the high gain as said low noise amplifier when said reception signal level is low. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification