CN101629996A

CN101629996A - Radio frequency structure for realizing function of switching dual-band GPS satellite signal into base band signal

Info

Publication number: CN101629996A
Application number: CN200910056551A
Authority: CN
Inventors: 王永泉
Original assignee: CHC TECHNOLOGY Co Ltd
Current assignee: CHC TECHNOLOGY Co Ltd; Shanghai Huace Navigation Technology Ltd
Priority date: 2009-08-18
Filing date: 2009-08-18
Publication date: 2010-01-20
Also published as: WO2011020399A1

Abstract

The invention relates to a radio frequency structure for realizing the function of switching dual-band GPS satellite signal into base band signal; wherein GPS satellite signal is divided into circuits of L1 frequency band and L2 frequency band, and generation circuits of local oscillator 1743MHz, 1059MHz, 336MHz and clock signal 25MHz, a processing circuit for converting down GPS satellite signal into intermediate frequency signal, and a circuit of I path and Q path digital signal obtained by processing the intermediate frequency signal by orthogonal demodulation, filtration and A/D conversion after being received. The difference between a primary local oscillator signal frequency of L1 and the L1 frequency band of GPS satellite signal is positive, the difference between a secondary local oscillator signal frequency of L2 and the L2 frequency band of GPS satellite signal is negative, and the primary local oscillator signal frequency of L1 and the primary local oscillator signal frequency of L2 are respectively generated by different frequency synthesizers. The adoption of the radio frequency structure not only solves the mutual interference problem of channel signals, but also enhances the signal-to-noise ratio of the system. The circuit structure is simple and practical, the working performance is stable and reliable, and the application range is wider.

Description

Realize that the double-frequency GPS satellite-signal is converted to the radio frequency structure of baseband signal function

Technical field

The present invention relates to GPS navigation location and fields of measurement, particularly double-frequency GPS satellite-signal receiving and processing device technical field is meant that specifically a kind of double-frequency GPS satellite-signal of realizing is converted to the radio frequency structure of baseband signal function.

Background technology

GPS (Global Positioning System) is a kind of satellite emission signal that utilizes, and the receiver received signal of earth surface or near floor level is measured the worldwide navigation positioning system of information such as observation position of thing and time.Gps satellite signal adopts typical CDMA (CDMA) modulation technique to synthesize, and its complete signal mainly comprises three kinds of components such as carrier wave, pseudo-random code and numeric data code.Signal carrier is in L-band, and the frequency of two carrier waves is remembered respectively and made L1 (1575.42MHz) and L2 (1227.6MHz).Every satellite is all launched broadcasting ranging code and navigation data on these two frequencies, but employed ranging code and other satellites are employed all different.Up-to-date and follow-up gps satellite also will be gone up these signals of emission at carrier wave L5 (1176.45MHz), but because the present invention only relates to the signal of L1 and L2 channel, so here do not discuss.Navigation data offers receiver, and with the definite position of satellite when transmitting, and ranging code makes receiver user can determine the transmission delay of signal, thereby determines the distance of satellite to the user.Therefore, the GPS receiver is vital subscriber equipment.

The GPS receiver circuit of practical application at present generally partly is made up of antenna element, radio frequency unit, GPS baseband digital signal processing unit etc.Wherein the effect of radio frequency unit is exactly that gps satellite signal with L1 channel and L2 channel leaches from neighbourhood noise, and suitable gain is provided, to satisfy the demand of follow-up baseband digital signal processing unit.We can directly leach the gps satellite signal of required channel at L-band in theory, carry out digital sample again through amplifying then.But because the loaded quality factor and the centre frequency of bandpass filter is proportional, under the constant situation of signal bandwidth, centre frequency is high more, and the quality factor of required wave filter will be high more.Shown in (1):

Q_{LD} = \frac{f_{C}}{{BW}_{3 dB}} . . . . . . (1)

F wherein _CBe the centre frequency of bandpass filter, BW _3dBThree dB bandwidth for bandpass filter.

The centre frequency of gps signal two carrier waves is very high and channel width is about 20MHz, directly leach required channel, then needs the very large wave filter of Q value, and present technical merit also is difficult to satisfy this index.Owing to the problem of high-frequency circuit at aspects such as gain, precision and stability, it is very unrealistic directly gps satellite signal to be carried out demodulation at high-frequency range in addition.Therefore, usual way is to use frequency mixer that the high frequency gps satellite signal is carried out down coversion.Can reduce technical indicator demand so greatly to wave filter, and the difficulty of having avoided high-frequency signal to be run in handling.But introduced the image frequency interference when utilizing frequency mixer to transform to the high frequency gps satellite signal than the Low Medium Frequency frequency, and the inhibition effect of utilizing wave filter that image frequency is disturbed depends on the frequency-splitting between image frequency frequency and the signal frequency, depends on the height of IF-FRE in other words.If the IF-FRE height, then signal and image frequency apart from each other, the image frequency composition just can be subjected to bigger inhibition so; Otherwise if IF-FRE is lower, then signal and image frequency are separated by not farly, and the filter effect that wave filter disturbs image frequency is just poor.Because channel is chosen in intermediate frequency and carries out, in like manner, higher IF-FRE is also higher to the requirement of channel selection filter, then image frequency suppress to select to form a pair of contradiction with channel, and IF-FRE be selected to this key of balance to contradiction.Usually it is better compromise to use two-stage or three frequency conversions to obtain in design proposal.

In the prior art, it is to select the local oscillation signal frequency of the intermediate frequency 1400MHz of L1 and L2 as the down coversion first time that a kind of design proposal is arranged, with L1 down-convert to 175.42MHz, L2 down-converts to 172.4MHz.Selecting the local oscillation signal frequency of 175MHz as the down coversion second time then, is i/q signal with the gps signal quadrature demodulation of L1 and L2 channel.Be transformed to the digital signal that can be used for subsequent treatment through A/D converter again.The production process of its local oscillation signal sees also shown in Figure 1.

Making frequency synthesizer 52 produce frequency from microprocessor control signal 50 is the signal 51 of 10MHz.By 2 frequency dividers 53 signal 51 is transformed to the signal 54 that frequency is 5MHz.Phase detector 55, loop filter 56 and voltage controlled oscillator 57 are formed a phase-locked loop.When loop-locking, voltage controlled oscillator 57 output frequencies are first local oscillation signal 58 of 1400MHz.First local oscillation signal 58 is carried out second local oscillation signal 63 that frequency division can obtain 175MHz by 8 frequency dividers 59.

In this design proposal, because two channels of L1 and L2 use the first identical local oscillation signal 58 to carry out the down coversion first time, cause crosstalking mutually of two channel signals inevitably, reduced the signal to noise ratio (S/N ratio) of system.

Summary of the invention

The objective of the invention is to have overcome above-mentioned shortcoming of the prior art, signal to noise ratio (S/N ratio), the circuit structure that provide a kind of mutual cross-interference issue that can effectively solve channel signal, improves system is simple and practical, use is convenient and swift, stable and reliable working performance, the scope of application realize that comparatively widely the double-frequency GPS satellite-signal is converted to the radio frequency structure of baseband signal function.

In order to realize above-mentioned purpose, the radio frequency structure that realization double-frequency GPS satellite-signal of the present invention is converted to the baseband signal function has following formation:

This realization double-frequency GPS satellite-signal is converted to the radio frequency structure of baseband signal function, comprise the antenna receiving module, its principal feature is, also comprise signal functional module, the first channel signal processing capacity module, second channel signal processing function module, local oscillation signal and clock signal generation functional module along separate routes in the described circuit structure, described antenna receiving module is connected with second channel signal processing function module with the described first channel signal processing capacity module respectively by described signal shunt functional module;

The described first channel signal processing capacity module comprises the first channel signal one-level frequency conversion function circuit and the first channel signal demodulation process circuit, and described signal functional module along separate routes is connected with the base band signal process circuit with the first channel signal demodulation process circuit by the described first channel signal one-level frequency conversion function circuit successively;

Described second channel signal processing function module comprises second channel signal one-level frequency conversion function circuit and second channel signal demodulation process circuit, and described signal functional module along separate routes is connected with described base band signal process circuit with second channel signal demodulation process circuit by described second channel signal one-level frequency conversion function circuit successively;

Described local oscillation signal and clock signal produce functional module the first channel signal one-level local oscillation signal that is produced are delivered in the described first channel signal one-level frequency conversion function circuit, described local oscillation signal and clock signal produce functional module the second channel signal one-level local oscillation signal that is produced are delivered in the described second channel signal one-level frequency conversion function circuit, described local oscillation signal and clock signal produce functional module the secondary local oscillation signal that is produced are delivered to respectively in described first channel signal demodulation process circuit and the second channel signal demodulation process circuit, and described local oscillation signal and clock signal produce functional module the clock signal of system that is produced are delivered in the described base band signal process circuit, and the described first channel signal one-level local oscillation signal is different with the frequency of second channel signal one-level local oscillation signal.

This realization double-frequency GPS satellite-signal is converted to the centre frequency of the centre frequency of first channel signal in the gps satellite signal in the radio frequency structure of baseband signal function greater than the second channel signal in the described gps satellite signal, the described first channel signal one-level local oscillation signal frequency is greater than the centre frequency of first channel signal in the described gps satellite signal, and described second channel signal one-level local oscillation signal frequency is less than the centre frequency of the second channel signal in the described gps satellite signal.

The first channel signal one-level local oscillation signal frequency that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function is 1743MHz.

The second channel signal one-level local oscillation signal frequency that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function is 1059MHz.

This realization double-frequency GPS satellite-signal is converted to local oscillation signal in the radio frequency structure of baseband signal function and clock signal and produces and comprise in the functional module that reference clock signal produces circuit, the first channel signal one-level local oscillation signal produces circuit, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and clock signal of system produces circuit, described reference clock signal produces circuit and produces circuit with the described first channel signal one-level local oscillation signal respectively, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and is connected with clock signal of system generation circuit, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in the described first channel signal one-level frequency conversion function circuit, described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in the described second channel signal one-level frequency conversion function circuit, described secondary local oscillation signal produces circuit the secondary local oscillation signal that is produced is delivered to respectively in described first channel signal demodulation process circuit and the second channel signal demodulation process circuit, and described clock signal of system generation circuit is delivered to the clock signal of system that is produced in the described base band signal process circuit.

This realization double-frequency GPS satellite-signal is converted to the first channel signal one-level local oscillation signal in the radio frequency structure of baseband signal function, and to produce circuit be frequency synthesizer circuit.

This realization double-frequency GPS satellite-signal is converted to the first channel signal one-level local oscillation signal in the radio frequency structure of baseband signal function and produces circuit and comprise first pre-divider, first phase detector, first loop filter, first voltage controlled oscillator and first frequency divider, described first pre-divider, first phase detector, first loop filter and first voltage controlled oscillator are connected in series in described reference clock signal successively and produce between the circuit and the first channel signal one-level frequency conversion function circuit, and the described first frequency divider cross-over connection is between described first voltage controlled oscillator and first phase detector.

This realization double-frequency GPS satellite-signal is converted to second channel signal one-level local oscillation signal in the radio frequency structure of baseband signal function, and to produce circuit be frequency synthesizer circuit.

This realization double-frequency GPS satellite-signal is converted to second channel signal one-level local oscillation signal in the radio frequency structure of baseband signal function and produces circuit and comprise second pre-divider, second phase detector, second loop filter, second voltage controlled oscillator and second frequency divider, described second pre-divider, second phase detector, second loop filter and second voltage controlled oscillator are connected in series in described reference clock signal successively and produce between circuit and the second channel signal one-level frequency conversion function circuit, and the described second frequency divider cross-over connection is between described second voltage controlled oscillator and second phase detector.

This realization double-frequency GPS satellite-signal is converted to secondary local oscillation signal in the radio frequency structure of baseband signal function and produces circuit and comprise the 3rd pre-divider, the 3rd phase detector, the 3rd loop filter, the 3rd voltage controlled oscillator and tri-frequency divider, described reference clock signal produces circuit successively by described the 3rd pre-divider, the 3rd phase detector, the 3rd loop filter and the 3rd voltage controlled oscillator are connected to described first channel signal demodulation process circuit and second channel signal demodulation process circuit respectively, and described tri-frequency divider cross-over connection is between described the 3rd voltage controlled oscillator and the 3rd phase detector.

This realization double-frequency GPS satellite-signal is converted to clock signal of system in the radio frequency structure of baseband signal function and produces circuit and comprise comparer, and described comparer is connected to described reference clock signal and produces between circuit and the base band signal process circuit.

This realization double-frequency GPS satellite-signal is converted to reference clock signal in the radio frequency structure of baseband signal function and produces circuit and can be frequency synthesizer circuit, comprising the temperature compensating crystal oscillator and the frequency synthesizer of phase locking of high frequency stability, described temperature compensating crystal oscillator produces circuit, second channel signal one-level local oscillation signal generation circuit, secondary local oscillation signal generation circuit and clock signal of system generation circuit with the described first channel signal one-level local oscillation signal respectively by described frequency synthesizer of phase locking and is connected.

This realization double-frequency GPS satellite-signal is converted to reference clock signal in the radio frequency structure of baseband signal function and produces circuit and also can be crystal oscillator.

The first channel signal one-level frequency conversion function circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises first bandpass filter and first frequency mixer, described signal functional module along separate routes is connected with the described first channel signal demodulation process circuit with first frequency mixer by described first bandpass filter successively, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in described first frequency mixer.

This realization double-frequency GPS satellite-signal is converted between first bandpass filter in the radio frequency structure of baseband signal function and first frequency mixer and also is serially connected with first low noise amplifier.

This realization double-frequency GPS satellite-signal is converted in the first channel signal one-level frequency conversion function circuit in the radio frequency structure of baseband signal function and also comprises second bandpass filter and first variable gain amplifier, described second bandpass filter and first variable gain amplifier are connected in series between described first frequency mixer and the described first channel signal demodulation process circuit successively, and the control input end of described first variable gain amplifier is connected with described base band signal process circuit.

The second channel signal one-level frequency conversion function circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises the 3rd bandpass filter and second frequency mixer, described signal functional module along separate routes is connected with described second channel signal demodulation process circuit with second frequency mixer by described the 3rd bandpass filter successively, and described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in described second frequency mixer.

This realization double-frequency GPS satellite-signal is converted between the 3rd bandpass filter in the radio frequency structure of baseband signal function and second frequency mixer and also is serially connected with second low noise amplifier.

This realization double-frequency GPS satellite-signal is converted in the second channel signal one-level frequency conversion function circuit in the radio frequency structure of baseband signal function and also comprises the four-tape bandpass filter and second variable gain amplifier, the described four-tape bandpass filter and second variable gain amplifier are connected in series between described second frequency mixer and the described second channel signal demodulation process circuit successively, and the control input end of described second variable gain amplifier is connected with described base band signal process circuit.

The first channel signal demodulation process circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises the first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit, and the described first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit are connected in series between described first channel signal one-level frequency conversion function circuit and the base band signal process circuit.

The first channel signal quadrature demodulation filtering circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises first signal functional module along separate routes, first detuner, second detuner, first low-pass filter, second low-pass filter and phase shifter, described first signal functional module along separate routes is connected with the described first channel signal analog to digital conversion circuit with first low-pass filter by described first detuner successively, and described first signal functional module along separate routes is connected with the described first channel signal analog to digital conversion circuit with second low-pass filter by described second detuner successively, described secondary local oscillation signal produces circuit and is connected with described first detuner, and described secondary local oscillation signal generation circuit is connected with described second detuner by described phase shifter.

The first channel signal analog to digital conversion circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises first analog to digital converter and second analog to digital converter, described first analog to digital converter is connected between described first low-pass filter and the base band signal process circuit, described second analog to digital converter is connected between described second low-pass filter and the base band signal process circuit, and described clock signal of system is delivered to described first analog to digital converter and second analog to digital converter as sampled clock signal.

This realization double-frequency GPS satellite-signal be converted in the radio frequency structure of baseband signal function first signal along separate routes functional module be power divider.

The second channel signal demodulation process circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit, and described second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit are connected in series between described second channel signal one-level frequency conversion function circuit and the base band signal process circuit.

The second channel signal in orthogonal demodulation filtering circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises secondary signal functional module along separate routes, the 3rd detuner, the 4th detuner, the 3rd low-pass filter, the 4th low-pass filter and phase shifter, described secondary signal functional module along separate routes is connected with described second channel signal analog to digital conversion circuit with the 3rd low-pass filter by described the 3rd detuner successively, and described secondary signal functional module along separate routes is connected with described second channel signal analog to digital conversion circuit with the 4th low-pass filter by described the 4th detuner successively, described secondary local oscillation signal produces circuit and is connected with described the 3rd detuner, and described secondary local oscillation signal generation circuit is connected with described the 4th detuner by described phase shifter.

The second channel signal analog to digital conversion circuit that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises the 3rd analog to digital converter and the 4th analog to digital converter, described the 3rd analog to digital converter is connected between described the 3rd low-pass filter and the base band signal process circuit, described the 4th analog to digital converter is connected between described the 4th low-pass filter and the base band signal process circuit, and described clock signal of system is delivered to described the 3rd analog to digital converter and the 4th analog to digital converter as sampled clock signal.

This realization double-frequency GPS satellite-signal be converted in the radio frequency structure of baseband signal function secondary signal along separate routes functional module be power divider.

The antenna receiving module that this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function comprises antenna element and signal amplifier, and described antenna element is connected to described signal functional module along separate routes by described signal amplifier.

This realization double-frequency GPS satellite-signal is converted in the antenna receiving module in the radio frequency structure of baseband signal function and also comprises low noise amplifier in advance, and described low noise amplifier in advance is serially connected with between described antenna element and the signal amplifier.

This realization double-frequency GPS satellite-signal be converted in the radio frequency structure of baseband signal function signal along separate routes functional module be power divider.

Adopted the realization double-frequency GPS satellite-signal of this invention to be converted to the radio frequency structure of baseband signal function, produced the 25MHz reference clock signal by frequency synthesizer or crystal oscillator.Is the first order local oscillation signal that reference frequency produces first channel signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 1743MHz.Is the first order local oscillation signal that reference frequency produces the second channel signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 1059MHz.Is that reference frequency produces second level local oscillation signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 336MHz.Since the first order local oscillation signal frequency of first channel signal and second channel signal from far away as far as possible, thereby reduced separately local oscillation signal to the interference of one other channel.And adopt the independent frequency compositor to produce these two kinds of local oscillation signals and also reduced interfering with each other of two channels, not only make the mutual cross-interference issue of channel signal of the prior art obtain effective solution, and improved the signal to noise ratio (S/N ratio) of system.Circuit structure is simple and practical, use is convenient and swift, stable and reliable working performance, the scope of application are comparatively extensive, for receiving gps signal and determining that thus the further improvement and the optimization of radio circuit scheme of the double-frequency GPS receiver of position data established solid foundation.

Description of drawings

Fig. 1 is converted to the generation circuit theory diagrams of the local oscillation signal in the baseband signal functional circuit for double-frequency GPS satellite-signal of the prior art.

Fig. 2 is converted to the integrated circuit structural representation of the radio frequency structure of baseband signal function for realization double-frequency GPS satellite-signal of the present invention.

Fig. 3 is converted to gps satellite signal in the radio frequency structure of baseband signal function is divided into L1 channel and L2 channel after antenna receives circuit theory diagrams for realization double-frequency GPS satellite-signal of the present invention.

Fig. 4 is converted to the generation circuit theory diagrams of local oscillation signal 1743MHz, 1059MHz, 336MHz and clock signal 25MHz in the radio frequency structure of baseband signal function for realization double-frequency GPS satellite-signal of the present invention.

Fig. 5 is converted to circuit theory diagrams that gps satellite signal down-converted to intermediate-freuqncy signal in the radio frequency structure of baseband signal function for realization double-frequency GPS satellite-signal of the present invention.

Fig. 6 is converted to intermediate-freuqncy signal in the radio frequency structure of baseband signal function is converted to I road and Q way word signal through quadrature demodulation, filtering, A/D circuit theory diagrams for realization double-frequency GPS satellite-signal of the present invention.

Embodiment

In order more to be expressly understood technology contents of the present invention, describe in detail especially exemplified by following examples.

See also Fig. 2 to shown in Figure 6, this realization double-frequency GPS satellite-signal is converted to the radio frequency structure of baseband signal function, comprise the antenna receiving module, wherein, also comprise signal functional module, the first channel signal processing capacity module, second channel signal processing function module, local oscillation signal and clock signal generation functional module along separate routes in the described circuit structure, described antenna receiving module is connected with second channel signal processing function module with the described first channel signal processing capacity module respectively by described signal shunt functional module;

The described first channel signal processing capacity module comprises the first channel signal one-level frequency conversion function circuit and the first channel signal demodulation process circuit, and described signal functional module along separate routes is connected with described outside base band signal process circuit with the first channel signal demodulation process circuit by the described first channel signal one-level frequency conversion function circuit successively;

Wherein, the centre frequency of first channel signal in the described gps satellite signal is greater than the centre frequency of the second channel signal in the described gps satellite signal, the described first channel signal one-level local oscillation signal frequency is greater than the centre frequency of first channel signal in the described gps satellite signal, and described second channel signal one-level local oscillation signal frequency is less than the centre frequency of the second channel signal in the described gps satellite signal.

In the specific embodiment of the present invention, the described first channel signal one-level local oscillation signal frequency is 1743MHz, and described second channel signal one-level local oscillation signal frequency is 1059MHz.

Simultaneously, this realization double-frequency GPS satellite-signal is converted to local oscillation signal in the radio frequency structure of baseband signal function and clock signal and produces and comprise in the functional module that reference clock signal produces circuit, the first channel signal one-level local oscillation signal produces circuit, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and clock signal of system produces circuit, described reference clock signal produces circuit and produces circuit with the described first channel signal one-level local oscillation signal respectively, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and is connected with clock signal of system generation circuit, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in the described first channel signal one-level frequency conversion function circuit, described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in the described second channel signal one-level frequency conversion function circuit, described secondary local oscillation signal produces circuit the secondary local oscillation signal that is produced is delivered to respectively in described first channel signal demodulation process circuit and the second channel signal demodulation process circuit, and described clock signal of system generation circuit is delivered to the clock signal of system that is produced in the described base band signal process circuit.

Wherein, it is frequency synthesizer circuit that this first channel signal one-level local oscillation signal produces circuit, comprising first pre-divider 160, first phase detector 113, first loop filter 116, first voltage controlled oscillator 119 and first frequency divider 163, described first pre-divider 160, first phase detector 113, first loop filter 116 and first voltage controlled oscillator 119 are connected in series in described reference clock signal successively and produce between the circuit and the first channel signal one-level frequency conversion function circuit, and 163 cross-over connections of described first frequency divider are between described first voltage controlled oscillator 119 and first phase detector 113.

It is frequency synthesizer circuit that described second channel signal one-level local oscillation signal produces circuit, comprising second pre-divider 161, second phase detector 114, second loop filter 117, second voltage controlled oscillator 120 and second frequency divider 164, described second pre-divider 161, second phase detector 114, second loop filter 117 and second voltage controlled oscillator 120 are connected in series in described reference clock signal successively and produce between circuit and the second channel signal one-level frequency conversion function circuit, and 164 cross-over connections of described second frequency divider are between described second voltage controlled oscillator 120 and second phase detector 114.

It is frequency synthesizer circuit that described secondary local oscillation signal produces circuit, comprising the 3rd pre-divider 162, the 3rd phase detector 115, the 3rd loop filter 118, the 3rd voltage controlled oscillator 121 and tri-frequency divider 165, described reference clock signal produces circuit successively by described the 3rd pre-divider 162, the 3rd phase detector 115, the 3rd loop filter 118 and the 3rd voltage controlled oscillator 121 are connected to described first channel signal demodulation process circuit and second channel signal demodulation process circuit respectively, and described tri-frequency divider 165 cross-over connections are between described the 3rd voltage controlled oscillator 121 and the 3rd phase detector 115.

Described clock signal of system produces circuit and comprises comparer 128, and described comparer 128 is connected to described reference clock signal and produces between circuit and the base band signal process circuit.

Described reference clock signal produces circuit can be frequency synthesizer circuit, comprising the temperature compensating crystal oscillator and the frequency synthesizer of phase locking of high frequency stability, described temperature compensating crystal oscillator produces circuit, second channel signal one-level local oscillation signal generation circuit, secondary local oscillation signal generation circuit and clock signal of system generation circuit with the described first channel signal one-level local oscillation signal respectively by described frequency synthesizer of phase locking and is connected.

Simultaneously, described reference clock signal generation circuit also can be crystal oscillator.

Be converted in the radio frequency structure of baseband signal function at this realization double-frequency GPS satellite-signal, the described first channel signal one-level frequency conversion function circuit comprises first bandpass filter 131 and first frequency mixer 135, described signal functional module along separate routes is connected with the described first channel signal demodulation process circuit with first frequency mixer 135 by described first bandpass filter 131 successively, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in described first frequency mixer 135.

Simultaneously, also be serially connected with first low noise amplifier 133 between described first bandpass filter 131 and first frequency mixer 135; Also comprise second bandpass filter 137 and first variable gain amplifier 139 in the described first channel signal one-level frequency conversion function circuit, described second bandpass filter 137 and first variable gain amplifier 139 are connected in series between described first frequency mixer 135 and the described first channel signal demodulation process circuit successively, and the control input end of described first variable gain amplifier 139 is connected with described base band signal process circuit.

Moreover, be converted in the radio frequency structure of baseband signal function at this realization double-frequency GPS satellite-signal, described second channel signal one-level frequency conversion function circuit comprises the 3rd bandpass filter 231 and second frequency mixer 235, described signal functional module along separate routes is connected with described second channel signal demodulation process circuit with second frequency mixer 235 by described the 3rd bandpass filter 231 successively, and described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in described second frequency mixer 235.

Simultaneously, also be serially connected with second low noise amplifier 233 between described the 3rd bandpass filter 231 and second frequency mixer 235; Also comprise the four-tape bandpass filter 237 and second variable gain amplifier 239 in the described second channel signal one-level frequency conversion function circuit, the described four-tape bandpass filter 237 and second variable gain amplifier 239 are connected in series between described second frequency mixer 235 and the described second channel signal demodulation process circuit successively, and the control input end of described second variable gain amplifier 239 is connected with described base band signal process circuit.

In addition, be converted in the radio frequency structure of baseband signal function at this realization double-frequency GPS satellite-signal, the described first channel signal demodulation process circuit comprises the first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit, and the described first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit are connected in series between described first channel signal one-level frequency conversion function circuit and the base band signal process circuit.

Wherein, the described first channel signal quadrature demodulation filtering circuit comprises first signal functional module 141 along separate routes, first detuner 144, second detuner 145, first low-pass filter 148, second low-pass filter 149 and phase shifter 126, described first signal functional module 141 along separate routes is connected with the described first channel signal analog to digital conversion circuit with first low-pass filter 148 by described first detuner 144 successively, and described first signal functional module 141 along separate routes is connected with the described first channel signal analog to digital conversion circuit with second low-pass filter 149 by described second detuner 145 successively, described secondary local oscillation signal produces circuit and is connected with described first detuner 144, and described secondary local oscillation signal generation circuit is connected with described second detuner 145 by phase shifter 126.

The described first channel signal analog to digital conversion circuit comprises first analog to digital converter 152 and second analog to digital converter 153, described first analog to digital converter 152 is connected between described first low-pass filter 148 and the base band signal process circuit, described second analog to digital converter 153 is connected between described second low-pass filter 149 and the base band signal process circuit, described system clock 125 is delivered to described first analog to digital converter 152 and second analog to digital converter 153 as sampling clock, and described first signal shunt functional module 141 is a power divider.

And, be converted in the radio frequency structure of baseband signal function at this realization double-frequency GPS satellite-signal, described second channel signal demodulation process circuit comprises second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit, and described second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit are connected in series between described second channel signal one-level frequency conversion function circuit and the base band signal process circuit.

Wherein, described second channel signal in orthogonal demodulation filtering circuit comprises secondary signal functional module 241 along separate routes, the 3rd detuner 244, the 4th detuner 245, the 3rd low-pass filter 248, the 4th low-pass filter 249 and phase shifter 126, described secondary signal functional module 241 along separate routes is connected with described second channel signal analog to digital conversion circuit with the 3rd low-pass filter 248 by described the 3rd detuner 244 successively, and described secondary signal functional module 241 along separate routes is connected with described second channel signal analog to digital conversion circuit with the 4th low-pass filter 249 by described the 4th detuner 245 successively, described secondary local oscillation signal produces circuit and is connected with described the 3rd detuner 244, and described secondary local oscillation signal generation circuit is connected with described the 4th detuner 245 by phase shifter 126.

Described second channel signal analog to digital conversion circuit comprises the 3rd analog to digital converter 252 and the 4th analog to digital converter 253, described the 3rd analog to digital converter 252 is connected between described the 3rd low-pass filter 248 and the base band signal process circuit, described the 4th analog to digital converter 253 is connected between described the 4th low-pass filter 249 and the base band signal process circuit, described clock signal of system is delivered to described the 3rd analog to digital converter and the 4th analog to digital converter as sampled clock signal, and described secondary signal shunt functional module 241 is a power divider.

Moreover, this realization double-frequency GPS satellite-signal is converted in the radio frequency structure of baseband signal function, described antenna receiving module comprises antenna element 100 and signal amplifier 103, and described antenna element 100 is connected to described signal functional module along separate routes by described signal amplifier 103; Also comprise low noise amplifier 101 in advance in the described antenna receiving module, described low noise amplifier 101 in advance is serially connected with between described antenna element 100 and the signal amplifier 103; Described signal functional module along separate routes is a power divider 105.

In the middle of practical application, see also shown in Figure 2ly, it is the synoptic diagram of whole structural scheme of the present invention.

Being received and by the gps satellite signal that amplifier 3 amplifies, be divided into two paths of signals by power splitter 4 by dual-band antenna 1, is respectively the signal 5 (centre frequency is 1575.42MHz) of L1 channel and the signal 6 (centre frequency is 1227.6MHz) of L2 channel.At the L1 channel, signal 5 is earlier through a passive bandpass filters 8, and filtering obtains signal 10, and the first order local oscillation signal 30 by frequency mixer 13 and L1 carries out mixing then.Wherein the frequency of local oscillation signal 30 is 1743MHz.The signal 136 that obtains after the mixing comprises upper side band and lower sideband.Carry out filtering with the signal 17 that obtains after 19 pairs of mixing of bandpass filter, the noise signal that filtering upper side band signal and leakage are come in, obtaining centre frequency is the intermediate-freuqncy signal 21 of 167.58MHz.We realize automatic gain control (AGC) function with the loop that comprises a variable gain amplifier 23 subsequently, guarantee that signal has enough dynamic ranges.Signal 25 after intermediate-freuqncy signal 21 is amplified through variable gain amplifier 23 will obtain a stable signal amplitude.The signal 34 of control variable gain amplifier 23 gain amplifiers is from baseband processing circuitry.The intermediate-freuqncy signal 25 of L1 channel and secondary local oscillation signal 32 demodulate i/q signal I1 and the Q1 of L1 through detuner 27, and frequency is 420KHz.Carry out analog to digital conversion by 36 couples of signal I1 of A/D converter and Q1, obtain digital signal 39.Sending into baseband processing circuitry then further handles.

The above-mentioned signal processing of L2 channel and L1 channel duplicates, but the frequency difference of each point.Wherein first order local oscillation signal 31 frequencies of L2 are 1059MHz; Intermediate-freuqncy signal 22 centre frequencies that mixing for the first time obtains are 168.6MHz; I/q signal I2 that demodulation obtains and Q2 frequency are 600KHz.

Produce 25MHz reference clock signal 12 by frequency synthesizer or crystal oscillator 7.Frequency synthesizer 14 is the first order local oscillation signal 30 (frequency is 1743MHz) that reference frequency produces the L1 channel with signal 12.Frequency synthesizer 16 is the first order local oscillation signal 31 (frequency is 1059MHz) that reference frequency produces the L2 channel with signal 12.Frequency synthesizer 29 is that reference frequency produces second level local oscillation signal 32 (frequency is 336MHz) with signal 12.The first order local oscillation signal frequency of L1 channel and L2 channel from far away as far as possible, thereby reduce separately local oscillation signal to the interference of one other channel.Adopt the independent frequency compositor to produce these two kinds of local oscillation signals and also reduced interfering with each other of two channels.

See also shown in Figure 3ly again, wherein provide gps satellite signal is divided into L1 and L2 channel after antenna receives process synoptic diagram.

The major function of antenna 100 is to receive aerial gps satellite signal, thereby provides comparatively pure complete satellite-signal for GPS receiver radio frequency front end.In total system the internal noise of element circuits at different levels to cascade after the response of overall noise factor different, the noise figure of the element circuit that progression is forward more is big more to the influence of overall noise factor.Therefore, overall noise factor depends primarily on the noise figure of what element circuit of foremost, and wherein the thermonoise of antenna element is to receiver performance impact maximum.The gps satellite signal that antenna 100 receives at first will through a low noise in advance amplifier 101 amplify, in fact low noise amplifier 101 has in advance determined the final noise figure of whole receiver.Gps satellite signal 102 through low noise amplifier amplification in advance further improves gain through signal amplifier 103 again.The gain that amplifier 103 provides mainly is in order to compensate the Insertion Loss of transmission line, power splitter and wave filter, can to increase the reverse isolation degree again simultaneously, guaranteeing the dynamic range of gps satellite signal.Amplifier 103 output gps satellite signals 104 are through being divided into the signal 107 (its centre frequency is 1227.6MHz) of signal 108 that two paths of signals is respectively the L1 channel (its centre frequency is 1575.42MHz) and L2 channel behind the power splitter 105.

See also shown in Figure 4ly again, what wherein describe is the production process of local oscillation signal 1743MHz, 1059MHz, 336MHz and clock signal 25MHz.

5MHz that signal 110 can be produced by the temperature compensating crystal oscillator of a high frequency stability or the reference frequency signal of 10MHz also can be outside 5MHz or 10MHz reference clocks.Frequency synthesizer of phase locking 111 obtains reference clock signal 112 with signal 110 frequencys multiplication to 25MHz.Phase detector 113, loop filter 116 and phase-locked loop circuit of voltage controlled oscillator 119 common compositions, adjust the frequency dividing ratio R1 of pre-divider 160 and the frequency dividing ratio N1 of frequency divider 163, make N1/R1 1743/25 can obtain the first order local oscillation signal 122 that frequency is the L1 of 1743MHz.

Similarly, adjust the frequency dividing ratio R2 of pre-divider 161 and the frequency dividing ratio N2 of frequency divider 164, make N2/R2 1059/25 obtain the first order local oscillation signal 123 that frequency is the L2 of 1059MHz; Adjust the frequency dividing ratio R3 of pre-divider 162 and the frequency dividing ratio N3 of frequency divider 165, make N3/R3 336/25 can obtain the second level local oscillation signal 124 that frequency is 336MHz.Signal 112 obtains the system clock 125 that frequency is 25MHz after adjusting through comparer 128.Here we to select the first order local oscillation signal frequency of L1 be 1743MHz, the L1 frequency range 1575.42MHz difference of it and gps satellite signal is for just; Simultaneously we also to select the second level local oscillation signal frequency of L2 be 1059MHz, it with the L2 frequency range 1227.6MHz difference of gps satellite signal for bearing.This be for allow L1 channel and L2 channel first order local oscillation signal frequency from far away as far as possible, thereby reduce separately local oscillation signal to the interference of one other channel.Adopting independently phase-locked loop circuit to produce these two kinds of local oscillation signals also is in order to reduce interfering with each other of two channels.

See also shown in Figure 5ly again, it is the process synoptic diagram that about how gps satellite signal is down-converted to intermediate-freuqncy signal.

At the L1 channel, signal 130 is earlier through a bandpass filter 131, and its centre frequency is 1575.42MHz, and bandwidth is 20MHz.The signal 132 input low noise amplifiers 133 that filtering obtains amplify.Signal 134 after the amplification carries out mixing by the first order local oscillation signal 122 of frequency mixer 135 and L1.Wherein the frequency of local oscillation signal 122 is 1743MHz.The signal 136 that obtains after the mixing comprises upper side band and lower sideband.Is that the signal 136 that obtains after 137 pairs of mixing of bandpass filter of 20MHz carries out filtering with centre frequency for the 168.5MHz bandwidth, filtering upper side band signal and leak the noise signal of coming in, and obtaining centre frequency is the intermediate-freuqncy signal 138 of 167.58MHz.The intermediate-freuqncy signal 138 that obtains after the mixing has kept signal Doppler and PRN sign indicating number, and just carrier frequency has reduced.We realize automatic gain control (AGC) function with the loop that comprises a variable gain amplifier 139 at last, guarantee that signal has enough dynamic ranges.Signal 140 after intermediate-freuqncy signal 138 is amplified through variable gain amplifier 139 will obtain a stable signal amplitude.The signal 181 of control variable gain amplifier 139 gain amplifiers is from baseband processing circuitry.

At the L2 channel, signal 230 is earlier through a bandpass filter 231, and its centre frequency is 1227.6MHz, and bandwidth is 20MHz.The signal 232 input low noise amplifiers 233 that filtering obtains amplify.Signal 234 after the amplification carries out mixing by the first order local oscillation signal 123 of frequency mixer 235 and L2.Wherein the frequency of local oscillation signal 123 is 1059MHz.The signal 236 that obtains after the mixing comprises upper side band and lower sideband.Is that the signal 236 that obtains after 237 pairs of mixing of bandpass filter of 20MHz carries out filtering with centre frequency for the 168.5MHz bandwidth, filtering upper side band signal and leak the noise signal of coming in, and obtaining centre frequency is the intermediate-freuqncy signal 238 of 168.6MHz.The intermediate-freuqncy signal 238 that obtains after the mixing has kept signal Doppler and PRN sign indicating number, and just carrier frequency has reduced.We realize automatic gain control (AGC) function with the loop that comprises a variable gain amplifier 239 at last, guarantee that signal has enough dynamic ranges.Signal 240 after intermediate-freuqncy signal 238 is amplified through variable gain amplifier 239 will obtain a stable signal amplitude.The signal 182 of control variable gain amplifier 239 gain amplifiers is from baseband processing circuitry.

See also shown in Figure 6ly again, what wherein describe is intermediate-freuqncy signal is converted to I road and Q way word signal through quadrature demodulation, filtering, A/D process.

The intermediate-freuqncy signal processing procedure of L1 frequency range and L2 frequency range duplicates, and we are that example is described specifically with the L1 frequency range equally only at this.The intermediate-freuqncy signal 140 of L1 frequency range is divided into the signal 142 and 143 of two-way same magnitude and phase place through power splitter 141.Signal 142 and secondary local oscillator I road signal 124 demodulate the I signal 146 of L1 through detuner 144; Signal 143 and secondary local oscillator Q road signal 127 demodulate the Q signal 147 of L1 through detuner 145.Wherein secondary local oscillator Q road signal 127 is obtained for 90 ° through phase shifter 126 phase shifts by secondary local oscillator I road signal 124.

Wherein, I road signal 146 is low-pass filter 148 filtering of 12.5MHz through bandwidth, and obtaining carrier frequency is the signal 150 of 420KHz, carries out analog to digital conversion by 152 pairs of signals of A/D converter 150, obtains digital signal 154.Q road signal 147 is low-pass filter 149 filtering of 12.5MHz through bandwidth, and obtaining carrier frequency is the signal 151 of 420KHz, carries out analog to digital conversion by 153 pairs of signals of A/D converter 151, obtains digital signal 155.Similarly, we can obtain I way word signal 254 and Q way word signal 255 that carrier frequency is the L2 frequency range of 600KHz.Above-mentioned digital signal 154,155,254 and 255 all will be sent into baseband processing circuitry and further handle.

In the radio-frequency channel design proposal that the double-frequency GPS satellite-signal is transformed into the digital signal that can be used for Base-Band Processing of the present invention, comprise that gps satellite signal is divided into the process of L1 and L2 frequency range after antenna receives; The production process that comprises local oscillation signal 1743MHz, 1059MHz, 336MHz and clock signal 25MHz; Comprise the processing procedure that gps satellite signal is down-converted to intermediate-freuqncy signal; Comprise that intermediate-freuqncy signal is converted to the process of I road and Q way word signal through quadrature demodulation, filtering, A/D.

Wherein the first order local oscillation signal frequency of L1 is 1743MHz, and the L1 frequency range 1575.42MHz difference of it and gps satellite signal is for just; The second level local oscillation signal frequency of L2 is 1059MHz, and the L2 frequency range 1227.6MHz difference of it and gps satellite signal is for negative.

In the specific embodiment of the present invention, the first order local oscillation signal (its frequency is 1059MHz) of the first order local oscillation signal of L1 (its frequency is 1743MHz) and L2 is produced by different frequency synthesizers respectively.

Simultaneously, the used centre frequency of the present invention is the bandpass filter of 1575.42MHz, 1227.6MHz and 168.5MHz, and its bandwidth can be 20MHz but be not limited to 20MHz; Its cutoff frequency of the used low-pass filter of the present invention can be 12.5MHz but be not limited to 12.5MHz.And the used reference frequency of each frequency synthesizer that produces local oscillation signal can be 25MHz but is not limited to 25MHz.

Adopted above-mentioned realization double-frequency GPS satellite-signal to be converted to the radio frequency structure of baseband signal function, produced the 25MHz reference clock signal by frequency synthesizer or crystal oscillator.Is the first order local oscillation signal that reference frequency produces first channel signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 1743MHz.Is the first order local oscillation signal that reference frequency produces the second channel signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 1059MHz.Is that reference frequency produces second level local oscillation signal by frequency synthesizer with this reference clock signal, and correspondent frequency is 336MHz.Since the first order local oscillation signal frequency of first channel signal and second channel signal from far away as far as possible, thereby reduced separately local oscillation signal to the interference of one other channel.And adopt the independent frequency compositor to produce these two kinds of local oscillation signals and also reduced interfering with each other of two channels, not only make the mutual cross-interference issue of channel signal of the prior art obtain effective solution, and improved the signal to noise ratio (S/N ratio) of system.Circuit structure is simple and practical, use is convenient and swift, stable and reliable working performance, the scope of application are comparatively extensive, for receiving gps signal and determining that thus the further improvement and the optimization of radio circuit scheme of the double-frequency GPS receiver of position data established solid foundation.

In this instructions, the present invention is described with reference to its certain embodiments.But, still can make various modifications and conversion obviously and not deviate from the spirit and scope of the present invention.Therefore, instructions and accompanying drawing are regarded in an illustrative, rather than a restrictive.

Claims

1, a kind of double-frequency GPS satellite-signal of realizing is converted to the radio frequency structure of baseband signal function, comprise the antenna receiving module, it is characterized in that, also comprise signal functional module, the first channel signal processing capacity module, second channel signal processing function module, local oscillation signal and clock signal generation functional module along separate routes in the described circuit structure, described antenna receiving module is connected with second channel signal processing function module with the described first channel signal processing capacity module respectively by described signal shunt functional module;

2, realization double-frequency GPS satellite-signal according to claim 1 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the centre frequency of first channel signal in the described gps satellite signal is greater than the centre frequency of the second channel signal in the described gps satellite signal, the described first channel signal one-level local oscillation signal frequency is greater than the centre frequency of first channel signal in the described gps satellite signal, and described second channel signal one-level local oscillation signal frequency is less than the centre frequency of the second channel signal in the described gps satellite signal.

3, realization double-frequency GPS satellite-signal according to claim 2 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal one-level local oscillation signal frequency is 1743MHz.

4, realization double-frequency GPS satellite-signal according to claim 2 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal one-level local oscillation signal frequency is 1059MHz.

5, be converted to the radio frequency structure of baseband signal function according to each described realization double-frequency GPS satellite-signal in the claim 1 to 4, it is characterized in that, described local oscillation signal and clock signal produce and comprise in the functional module that reference clock signal produces circuit, the first channel signal one-level local oscillation signal produces circuit, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and clock signal of system produces circuit, described reference clock signal produces circuit and produces circuit with the described first channel signal one-level local oscillation signal respectively, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and is connected with clock signal of system generation circuit, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in the described first channel signal one-level frequency conversion function circuit, described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in the described second channel signal one-level frequency conversion function circuit, described secondary local oscillation signal produces circuit the secondary local oscillation signal that is produced is delivered to respectively in described first channel signal demodulation process circuit and the second channel signal demodulation process circuit, and described clock signal of system generation circuit is delivered to the clock signal of system that is produced in the described base band signal process circuit.

6, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, it is frequency synthesizer circuit that the described first channel signal one-level local oscillation signal produces circuit.

7, realization double-frequency GPS satellite-signal according to claim 6 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal one-level local oscillation signal produces circuit and comprises first pre-divider (160), first phase detector (113), first loop filter (116), first voltage controlled oscillator (119) and first frequency divider (163), described first pre-divider (160), first phase detector (113), first loop filter (116) and first voltage controlled oscillator (119) are connected in series in described reference clock signal successively and produce between the circuit and the first channel signal one-level frequency conversion function circuit, and described first frequency divider (163) cross-over connection is between described first voltage controlled oscillator (119) and first phase detector (113).

8, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, it is frequency synthesizer circuit that described second channel signal one-level local oscillation signal produces circuit.

9, realization double-frequency GPS satellite-signal according to claim 8 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal one-level local oscillation signal produces circuit and comprises second pre-divider (161), second phase detector (114), second loop filter (117), second voltage controlled oscillator (120) and second frequency divider (164), described second pre-divider (161), second phase detector (114), second loop filter (117) and second voltage controlled oscillator (120) are connected in series in described reference clock signal successively and produce between circuit and the second channel signal one-level frequency conversion function circuit, and described second frequency divider (164) cross-over connection is between described second voltage controlled oscillator (120) and second phase detector (114).

10, realization double-frequency GPS satellite-signal according to claim 8 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described secondary local oscillation signal produces circuit and comprises the 3rd pre-divider (162), the 3rd phase detector (115), the 3rd loop filter (118), the 3rd voltage controlled oscillator (121) and tri-frequency divider (165), described reference clock signal produces circuit successively by described the 3rd pre-divider (162), the 3rd phase detector (115), the 3rd loop filter (118) and the 3rd voltage controlled oscillator (121) are connected to described first channel signal demodulation process circuit and second channel signal demodulation process circuit respectively, and described tri-frequency divider (165) cross-over connection is between described the 3rd voltage controlled oscillator (121) and the 3rd phase detector (115).

11, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described clock signal of system produces circuit and comprises comparer (128), and described comparer (128) is connected to described reference clock signal and produces between circuit and the base band signal process circuit.

12, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, it is frequency synthesizer circuit that described reference clock signal produces circuit, comprising the temperature compensating crystal oscillator and the frequency synthesizer of phase locking of high frequency stability, described temperature compensating crystal oscillator produces circuit with the described first channel signal one-level local oscillation signal respectively by described frequency synthesizer of phase locking, second channel signal one-level local oscillation signal produces circuit, the secondary local oscillation signal produces circuit and is connected with clock signal of system generation circuit.

13, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, it is crystal oscillator that described reference clock signal produces circuit.

14, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal one-level frequency conversion function circuit comprises first bandpass filter (131) and first frequency mixer (135), described signal functional module along separate routes is connected with the described first channel signal demodulation process circuit with first frequency mixer (135) by described first bandpass filter (131) successively, and the described first channel signal one-level local oscillation signal produces circuit the first channel signal one-level local oscillation signal that is produced is delivered in described first frequency mixer (135).

15, realization double-frequency GPS satellite-signal according to claim 14 is converted to the radio frequency structure of baseband signal function, it is characterized in that, also be serially connected with first low noise amplifier (133) between described first bandpass filter (131) and first frequency mixer (135).

16, realization double-frequency GPS satellite-signal according to claim 14 is converted to the radio frequency structure of baseband signal function, it is characterized in that, also comprise second bandpass filter (137) and first variable gain amplifier (139) in the described first channel signal one-level frequency conversion function circuit, described second bandpass filter (137) and first variable gain amplifier (139) are connected in series between described first frequency mixer (135) and the described first channel signal demodulation process circuit successively, and the control input end of described first variable gain amplifier (139) is connected with described base band signal process circuit.

17, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal one-level frequency conversion function circuit comprises the 3rd bandpass filter (231) and second frequency mixer (235), described signal functional module along separate routes is connected with described second channel signal demodulation process circuit with second frequency mixer (235) by described the 3rd bandpass filter (231) successively, and described second channel signal one-level local oscillation signal produces circuit the second channel signal one-level local oscillation signal that is produced is delivered in described second frequency mixer (235).

18, realization double-frequency GPS satellite-signal according to claim 17 is converted to the radio frequency structure of baseband signal function, it is characterized in that, also be serially connected with second low noise amplifier (233) between described the 3rd bandpass filter (231) and second frequency mixer (235).

19, realization double-frequency GPS satellite-signal according to claim 17 is converted to the radio frequency structure of baseband signal function, it is characterized in that, also comprise four-tape bandpass filter (237) and second variable gain amplifier (239) in the described second channel signal one-level frequency conversion function circuit, described four-tape bandpass filter (237) and second variable gain amplifier (239) are connected in series between described second frequency mixer (235) and the described second channel signal demodulation process circuit successively, and the control input end of described second variable gain amplifier (239) is connected with described base band signal process circuit.

20, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal demodulation process circuit comprises the first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit, and the described first channel signal quadrature demodulation filtering circuit and the first channel signal analog to digital conversion circuit are connected in series between described first channel signal one-level frequency conversion function circuit and the base band signal process circuit.

21, realization double-frequency GPS satellite-signal according to claim 20 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal quadrature demodulation filtering circuit comprises first signal functional module (141) along separate routes, first detuner (144), second detuner (145), first low-pass filter (148), second low-pass filter (149) and phase shifter (126), described first signal functional module (141) along separate routes is connected with the described first channel signal analog to digital conversion circuit with first low-pass filter (148) by described first detuner (144) successively, and described first signal functional module (141) along separate routes is connected with the described first channel signal analog to digital conversion circuit with second low-pass filter (149) by described second detuner (145) successively, described secondary local oscillation signal produces circuit and is connected with described first detuner (144), and described secondary local oscillation signal generation circuit is connected with described second detuner (145) by described phase shifter (126).

22, realization double-frequency GPS satellite-signal according to claim 21 is converted to the radio frequency structure of baseband signal function, it is characterized in that, the described first channel signal analog to digital conversion circuit comprises first analog to digital converter (152) and second analog to digital converter (153), described first analog to digital converter (152) is connected between described first low-pass filter (148) and the base band signal process circuit, described second analog to digital converter (153) is connected between described second low-pass filter (149) and the base band signal process circuit, and described clock signal of system is delivered to described first analog to digital converter (152) and second analog to digital converter (153) as sampled clock signal.

23, realization double-frequency GPS satellite-signal according to claim 21 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described first signal functional module (141) along separate routes is a power divider.

24, realization double-frequency GPS satellite-signal according to claim 5 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal demodulation process circuit comprises second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit, and described second channel signal in orthogonal demodulation filtering circuit and second channel signal analog to digital conversion circuit are connected in series between described second channel signal one-level frequency conversion function circuit and the base band signal process circuit.

25, realization double-frequency GPS satellite-signal according to claim 24 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal in orthogonal demodulation filtering circuit comprises secondary signal functional module (241) along separate routes, the 3rd detuner (244), the 4th detuner (245), the 3rd low-pass filter (248), the 4th low-pass filter (249) and phase shifter (126), described secondary signal functional module (241) along separate routes is connected with described second channel signal analog to digital conversion circuit with the 3rd low-pass filter (248) by described the 3rd detuner (244) successively, and described secondary signal functional module (241) along separate routes is connected with described second channel signal analog to digital conversion circuit with the 4th low-pass filter (249) by described the 4th detuner (245) successively, described secondary local oscillation signal produces circuit and is connected with described the 3rd detuner (244), and described secondary local oscillation signal generation circuit is connected with described the 4th detuner (245) by described phase shifter (126).

26, realization double-frequency GPS satellite-signal according to claim 24 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described second channel signal analog to digital conversion circuit comprises the 3rd analog to digital converter (252) and the 4th analog to digital converter (253), described the 3rd analog to digital converter (252) is connected between described the 3rd low-pass filter (248) and the base band signal process circuit, described the 4th analog to digital converter (253) is connected between described the 4th low-pass filter (249) and the base band signal process circuit, and described clock signal of system is delivered to described the 3rd analog to digital converter (252) and the 4th analog to digital converter (253) as sampled clock signal.

27, realization double-frequency GPS satellite-signal according to claim 24 is converted to the radio frequency structure of baseband signal function, it is characterized in that, described secondary signal functional module (241) along separate routes is a power divider.

28, be converted to the radio frequency structure of baseband signal function according to each described realization double-frequency GPS satellite-signal in the claim 1 to 4, it is characterized in that, described antenna receiving module comprises antenna element (100) and signal amplifier (103), and described antenna element (100) is connected to described signal functional module along separate routes by described signal amplifier (103).

29, realization double-frequency GPS satellite-signal according to claim 28 is converted to the radio frequency structure of baseband signal function, it is characterized in that, also comprise low noise amplifier (101) in advance in the described antenna receiving module, described low noise amplifier (101) in advance is serially connected with between described antenna element (100) and the signal amplifier (103).

30, be converted to the radio frequency structure of baseband signal function according to each described realization double-frequency GPS satellite-signal in the claim 1 to 4, it is characterized in that, described signal functional module along separate routes is power divider (105).