High-frequency IC and GPS receiver
First Claim
Patent Images
1. An integrated circuit outputting a digital signal according to a received global positioning satellite (GPS) signal, comprising:
- a mixer down-converting the received GPS signal into an intermediate frequency signal with a center frequency lower than that of the received signal;
a first filter with a pass bandwidth narrower than a bandwidth of the intermediate frequency signal down-converted by the mixer to receive the intermediate frequency signal and to filter the intermediate frequency signal;
a second filter removing a signal outside a band of the intermediate frequency signal configured to filter the intermediate frequency signal after the intermediate frequency signal is filtered by the first filter; and
a preamplifier between the first filter and the second filter, said preamplifier amplifying the intermediate frequency signal,wherein the pass bandwidth of the first filter is selected based on improving a sensitivity of the integrated circuit defined by;
Δ
Sensitivity=Δ
SNR-LS, andwherein;
Δ
Sensitivity represents a variation of the sensitivity of the integrated circuit,Δ
SNR represents a SNR variation, andLS represents a signal loss of the first filter.
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Abstract
The high-frequency IC according to an embodiment of the invention includes a mixer down-converting the RF signal into an IF signal with a given center frequency lower than that of the RF signal, a first-order low-pass filter with a pass band set narrower than a bandwidth of the IF signal down-converted by the mixer, and an active low-pass filter removing a signal outside the bandwidth of the IF signal.
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Citations
18 Claims
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1. An integrated circuit outputting a digital signal according to a received global positioning satellite (GPS) signal, comprising:
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a mixer down-converting the received GPS signal into an intermediate frequency signal with a center frequency lower than that of the received signal; a first filter with a pass bandwidth narrower than a bandwidth of the intermediate frequency signal down-converted by the mixer to receive the intermediate frequency signal and to filter the intermediate frequency signal; a second filter removing a signal outside a band of the intermediate frequency signal configured to filter the intermediate frequency signal after the intermediate frequency signal is filtered by the first filter; and a preamplifier between the first filter and the second filter, said preamplifier amplifying the intermediate frequency signal, wherein the pass bandwidth of the first filter is selected based on improving a sensitivity of the integrated circuit defined by; Δ
Sensitivity=Δ
SNR-LS, andwherein; Δ
Sensitivity represents a variation of the sensitivity of the integrated circuit,Δ
SNR represents a SNR variation, andLS represents a signal loss of the first filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of outputting a digital signal according to a received signal, comprising:
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down-converting a received global positioning satellite (GPS) signal into an intermediate frequency signal with a center frequency lower than that of the received signal; filtering the intermediate frequency signal after down-converting the received GPS signal through a pass bandwidth narrower than a bandwidth of the intermediate frequency signal; and removing a signal outside a band of the intermediate frequency signal after filtering the intermediate frequency signal, wherein the pass bandwidth is selected based on improving a sensitivity of an integrated circuit, defined by; Δ
Sensitivity=Δ
SNR-LS, andwherein; Δ
Sensitivity represents a variation of the sensitivity of the integrated circuit,Δ
SNR represents a SNR variation, andLS represents a signal loss of a filter performing the filtering. - View Dependent Claims (12)
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13. An integrated circuit outputting a digital signal according to a received global positioning satellite (GPS) signal, comprising:
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a mixer down-converting the received GPS signal into an intermediate frequency signal with a center frequency lower than that of the received GPS signal; a first filter with a pass bandwidth narrower than a bandwidth of the intermediate frequency signal down-converted by the mixer to receive the intermediate frequency signal and to filter the intermediate frequency signal; and a second filter removing a signal outside a band of the intermediate frequency signal configured to filter the intermediate frequency signal after the intermediate frequency signal is filtered by the first filter, wherein the pass bandwidth of the first filter is selected on a basis of a sensitivity of the integrated circuit obtained by comparing a signal loss and a signal to noise ratio (SNR) variation in the first filter, wherein the sensitivity of the integrated circuit is defined by; Δ
Sensitivity=Δ
SNR-LS, and wherein Δ
Sensitivity represents a variation of the sensitivity of the integrated circuit, Δ
SNR represents the SNR variation, and LS represents a signal loss of the first filter. - View Dependent Claims (14, 15, 16)
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17. A method of outputting a digital signal according to a received global positioning satellite (GPS) signal, comprising:
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down-converting the received GPS signal into an intermediate frequency signal with a center frequency lower than that of the received signal; filtering the intermediate frequency signal after down-converting the received GPS signal through a pass bandwidth narrower than a bandwidth of the intermediate frequency signal; and removing a signal outside a band of the intermediate frequency signal after filtering the intermediate frequency signal, wherein the pass bandwidth is selected based on a sensitivity of an integrated circuit obtained by comparing a signal loss and a signal to noise ratio (SNR) variation in the filtering of the intermediate frequency signal, and wherein the sensitivity of the integrated circuit is defined by; Δ
Sensitivity=Δ
SNR-LS, andwherein Δ
Sensitivity represents the variation of the sensitivity of the integrated circuit, Δ
SNR represents the SNR variation, and LS represents the signal loss of a filter performing the filtering. - View Dependent Claims (18)
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Specification