Dual mode satellite signal receiver and method thereof
First Claim
1. A dual mode satellite signal receiver capable of supporting at least two global navigation satellite systems, the dual mode satellite signal receiver comprising:
- a frequency synthesizer operative to generate a local oscillator signal based on a reference frequency wherein the frequency synthesizer is capable of supporting multiple reference frequencies;
a mixer operative to mix the local oscillator signal with a satellite signal and outputting a mixed signal where the mixed signal comprises a signal in an intermediate frequency band;
a first filter operative to filter the mixed signal to reject an image signal and output an actual signal;
a second filter operative to filter the actual signal received from the first filter to output a signal in a predetermined bandwidth based on a mode of the receiver; and
a variable gain amplifier operative to amplify the signal received from the second filter to a predetermined level and output the amplified signal,wherein the variable gain amplifier comprises and which comprises an exponential current generator operative to generate a first current and a second current such that a ratio of the first current to the second current varies exponentially to a linear-gain-control voltage received from an automatic gain control loop;
an exponential current-to-voltage converter operative to convert the first current and the second current into voltages; and
an amplifier operative to amplify an input signal by a gain based on the voltages from the exponential current-to-voltage converter.
1 Assignment
0 Petitions
Accused Products
Abstract
A dual mode satellite signal receiver capable of supporting at least two global navigation satellite systems and a satellite signal receiving method are provided. The dual mode satellite signal receiver comprises a frequency synthesizer for generating a local oscillator signal based on a reference frequency; a mixer for mixing the local oscillator signal with a satellite signal and outputting the mixed signal as a signal of an intermediate frequency band; a first filter for filtering the signal output from the mixer to reject an image signal and output only an actual signal; a second filter for filtering the actual signal to output only a predetermined bandwidth according to a positioning mode; and an amplifier for amplifying the second filter output signal to a predetermined level and outputting the amplified signal.
-
Citations
16 Claims
-
1. A dual mode satellite signal receiver capable of supporting at least two global navigation satellite systems, the dual mode satellite signal receiver comprising:
-
a frequency synthesizer operative to generate a local oscillator signal based on a reference frequency wherein the frequency synthesizer is capable of supporting multiple reference frequencies; a mixer operative to mix the local oscillator signal with a satellite signal and outputting a mixed signal where the mixed signal comprises a signal in an intermediate frequency band; a first filter operative to filter the mixed signal to reject an image signal and output an actual signal; a second filter operative to filter the actual signal received from the first filter to output a signal in a predetermined bandwidth based on a mode of the receiver; and a variable gain amplifier operative to amplify the signal received from the second filter to a predetermined level and output the amplified signal, wherein the variable gain amplifier comprises and which comprises an exponential current generator operative to generate a first current and a second current such that a ratio of the first current to the second current varies exponentially to a linear-gain-control voltage received from an automatic gain control loop;
an exponential current-to-voltage converter operative to convert the first current and the second current into voltages; and
an amplifier operative to amplify an input signal by a gain based on the voltages from the exponential current-to-voltage converter. - View Dependent Claims (2, 3, 4)
-
-
5. A dual mode satellite signal receiver capable of supporting at least two global navigation satellite systems, the dual mode satellite signal receiver comprising:
-
a frequency synthesizer operative to generate a local oscillator signal based on a reference frequency; a mixer operative to mix the local oscillator signal with a satellite signal and outputting a mixed signal where the mixed signal comprises a signal in an intermediate frequency band; a first filter operative to filter the mixed signal to reject an image signal and output an actual signal; a second filter operative to filter the actual signal received from the first filter to output a signal in a predetermined bandwidth based on a mode of the receiver; and a variable gain amplifier operative to amplify the signal received from the second filter to a predetermined level and output the amplified signal, wherein the variable gain amplifier is configured to utilize two internally-generated currents such that the ratio of the currents depend on either only NMOS or only PMOS transistors, wherein the variable gain amplifier comprises an exponential current generator operative to generate a first current and a second current such that a ratio of the first current to the second current varies exponentially to a linear-gain-control voltage received from an automatic gain control loop;
an exponential current-to-voltage converter operative to convert the first current and the second current into voltages; and
an amplifier operative to amplify an input signal by a gain based on the voltages from the exponential current-to-voltage converter. - View Dependent Claims (6, 7, 8, 9, 10, 11)
-
-
12. A satellite signal receiving method for a dual mode satellite signal receiver capable of supporting at least two global navigation satellite systems, the method comprising:
-
generating a local oscillator signal based on a reference frequency; mixing the local oscillator signal with a satellite signal and outputting a mixed signal where the mixed signal comprises a signal in an intermediate frequency band; filtering the output signal in the intermediate frequency band to reject an image signal and output an actual signal; filtering the actual signal to output a signal in a predetermined bandwidth based on a mode of the receiver; and amplifying the output signal in the predetermined bandwidth to a predetermined level, wherein the amplifying comprises generating a first current and a second current such that a ratio of the first current to the second current varies exponentially to a linear-gain-control voltage received from an automatic gain control loop;
converting the first current and the second current into respective voltages; and
amplifying the output signal in the predetermined bandwidth by a gain based on the two respective voltages. - View Dependent Claims (13, 14, 15, 16)
-
Specification