CN102931940A - Design method of navigation management signal dead zone filter - Google Patents

Abstract

The invention discloses a design method of a navigation management signal dead zone filter and belongs to the technical field of navigation management signal processing. According to the design method of the navigation management signal dead zone filter, a definite K type filter model is improved, a high-speed tube diode is loaded in an access of the filter model, the whole filtering effect is measured and analyzed, and the matching value of electrical inductance and capacitance in the filter in a dead zone is adjusted according to analysis of the filtering effect to achieve efficient filtering of frequency points of 1090 MHz, and therefore the technical problem that low-noise interference signals are hard to remove in processing of receiving of navigation management signals can be effectively solved.

Description

A kind of aviation management signal dead band filter design method

Technical field

The present invention is a kind of aviation management signal dead band filter design method, relates to aviation management signal processing technology field.

Background technology

Aviation management signal filtering design has material impact to the accuracy that airborne S pattern answer signal receives, be accompanied by in recent years China's aviation industry fast development, the particularly further opening of low altitude airspace, traditional air traffic control and safety guarantee means can not satisfy the instantly needs of development, with traditional A/C pattern difference S pattern be a kind of advanced person's radar inquiry system, can inquire aircraft selectively, and it is empty to carry out ground, absolutely empty bi-directional data communication, and have a sufficient aircraft coded residual, changed tradition take line-of-sight navigation as main General Aviation communication equipment, aloft surveillance equipment is near the limit, the spatial domain that the magnitude of traffic flow is larger such as airport and near low altitude airspace thereof, Automatic dependent surveillance broadcast take S pattern answering machine as main airborne equipment (Automatic Dependent Surveillance-Broadcast, ADS-B) thus system comparatively exactly the required aircraft of selective calling avoided the flight between the fellow to disturb, improved density and the utilance of flight space.

In the ADS-B system; S pattern answering machine often can be subject to being increased and the various disturbed conditions that bring by aerospace plane density; owing to having a more than bars transmission path between transmitter and the receiver; but only have one to be direct path between transmitter and receiver; it is outer all to be because the interference signal path that ground and building and so on reflect to form mostly; owing to using burst; the alternation sum that forms in time between direct signal and the reflected signal separates fully; the apparent number of its time missionary society's change transponder pulse; thereby cause decoding error or think mistakenly that multi-aircraft is arranged on every side; replying except being activated this inquisitor reception of replying of answering machine; also can be received by the inquisitor around other; these unnecessary answer signals can produce in receiving the inquisitor of this interference signal processes mistake; the two or more aircrafts nearer apart from the interval; their answer signal in time can overlapped (or crosstalking), processes mistake thereby can produce in ground receiver.

At present for above problem, Radar Design technical staff can only adopt the way of ground-plane antenna addressing to alleviate the problem that multipath causes passively, disturb the method for only taking filtering to reduce as much as possible the interference of unwanted signal for crosstalking with other, document " Gao Zhiqiang; explain bright and beautiful; Ye Yizheng. the high Q value of a kind of hyperfrequency CMOS Design of Bandpass [J]; electronic device .2006; 29(4): 992-995 " literary composition, introduced a kind of adjustable gain, high linearity, the CMOS integrated filter design of wide frequency domain, when centre frequency is 433MHz, the Q value is 40 o'clock, Spurious Free Dynamic Range is about 61.4dB, and can reach tuning to centre frequency and Q by the regulating circuit bias voltage, is the particularly method for designing of the aviation management signal of 1090MHz Frequency point of higher frequency but do not provide centre frequency, and need to add stable Power supply, power consumption is higher, and the filter effect on the passband is also asymmetric, is unfavorable for the down-converted of follow-up signal; Document " Luo Zhixian; Zhang Huaiwu; Cheng Lei. the design of microwave Interdigital Bandpass Filter [J]; science and technology and engineering .2011; 11(27): 6617-6620 " literary composition, adopt the Classic couture method, transform to interdigitated microstrip line construction by the lump lowpass structures, 2 band pass filters that frequency band is 1-1.4GHz and 1.42-2GHz have been designed, and by simulating, verifying the lumped element filters of this paper design solved in the high-frequency range inner structure complicated, bandwidth is hanged down and the too large problem of insertion loss, but designed band pass filter order is too high, in actual fabrication, tend to be subject to processing dimensional accuracy inadequate, the impact of the situations such as the frequency drift that the disengaging of copper line surface welding resisting layer causes and stray inductance are unstable is difficult to reach calculated value, and the bandpass filtering bandwidth of adding design is wide, can't solve the problem that high-frequency signal easily produces the frequency drift, the High frequency filter that is not suitable for the aviation management signal is processed.

In the air traffic control Data-Link; airborne answer signal usually can be subject to extraneous various interference effect; can't guarantee the accuracy of the response message that receiving equipment is received; bring larger error to decoding; affect airflight safety; and present research is mostly just to multipath; the larger distracter of amplitude such as crosstalk carries out simulation analysis; utilize high-speed a/d effectively to process through digital sample; but the interference signal of little noise is followed in receiving circuit always; art methods is difficult to solve the situation that occurs little noise interferences in the signal of reality is processed, and existence can't be eliminated the technical problem of these interference signal impact decoding accuracy of computations.

Summary of the invention

The technological deficiency that is difficult in the reception ﹠ disposal of the air control signal of reality, remove little noise interferences in order to overcome existing method, the invention provides a kind of aviation management signal dead band filter design method, the method is improved the constant-K filter model, the high speed tunnel diode is loaded in the path of filter model, by whole filter effect is carried out Measurement and analysis, matching value according to inductance and electric capacity in the filter of filter effect analysis and regulation dead band, reach the efficient filtering to the 1090MHz Frequency point, can effectively solve the technical problem that is difficult to remove little noise interferences in the aviation management signal reception ﹠ disposal.

The technical solution adopted for the present invention to solve the technical problems: a kind of aviation management signal dead band filter design method is characterized in may further comprise the steps:

1. choose 1090MHz as the centre frequency of design of filter, adopt band bandwidth to be not more than 6MHz, impedance is the design standard of 50 Ω, and choosing input respectively is 50 Ω with output impedance, and deciding K type normalization low pass filter design data with reference to high-order (is that impedance is that 1 Ω and cut-off frequency are

Approximate 0.159Hz) as reference filter, wherein the high-order constant-K filter can be composed in series by resolving into several 2 rank basic model low pass filters that are comprised of the series connection of 1H inductance and 1F Capacitance parallel connection ground connection;

2. choose the minimum exponent number low pass filter that meets the demands as design basis, design normalization low pass filter passes through following formula

$L_{\left(\mathrm{MID}\right)}=\frac{L_{\left(\mathrm{OLD}\right)}}{M}$

$C_{\left(\mathrm{MID}\right)}=\frac{C_{\left(\mathrm{OLD}\right)}}{M}$

Wherein: L _(OLD)Be the size of the inductance in the reference filter of choosing, C _(OLD)Be the capacitance size in the reference filter of choosing;

Calculate the cut-off frequency conversion, and carry out the characteristic impedance conversion by following formula

L _(NEW)=L _(MID)×K

$C_{\left(\mathrm{NEW}\right)}=\frac{C_{\left(\mathrm{MID}\right)}}{K}$

Wherein: L _(NEW)Be the size of the inductance in the low pass filter that designs, C _(NEW)Be the capacitance size in the low pass filter that designs, K is 50;

In the situation that do not change the wherein inductance value L through calculating of reference filter structure _(NEW)With capacitance C _(NEW)Replace with the fiducial value of original filter reference design, become the low pass filter with design band bandwidth;

3. utilize the band pass filter that K type normalization low pass filter data are come designing requirement of deciding that step 2 calculates, according to following circuit equivalent rule:

(1) uses capacitor C ₁With inductance L ₁Former path or the shunt capacitance C of replacing in parallel _A

$L_1=\frac{1}{{{\mathrm{\ω}}_0}^2\·C_A},$ C ₁=C _A

Wherein: C _ABe capacitance in the low pass filter, L ₁Be the inductance value after the equivalence, C ₁Be the capacitance after the equivalence, (2) use capacitor C ₂With inductance L ₂Former path or by-pass inductor L are replaced in series connection _B

${\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002384810000022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_B},$ L ₂=L _B

Wherein: L _BBe inductance value in the low pass filter, C ₂Be the capacitance after the equivalence, L ₂Be the inductance value after the equivalence,

(3) use capacitor C _3AWith inductance L _3ASeries connection, inductance L _3B, capacitor C _3BThree tunnel former path or the by-pass inductor L of replacing in parallel _CWith capacitor C _CIn parallel

L _3A=L _C， $C_{3A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_C},$ $L_{3B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_C},$ C _3B=C _C

Wherein: L _CBe inductance value in the low pass filter, C _CBe capacitance in the low pass filter, L _3ABe the inductance value in the series arm after the equivalence, C _3ABe the capacitance in the series arm after the equivalence, C _3BBe the capacitance after the equivalence, L _3BBe the inductance value after the equivalence,

(4) use inductance L _4A, capacitor C _4AAnd inductance L _4BWith capacitor C _4BSeries connection replaces inductance L after in parallel _DWith capacitor C _DSeries connection L _4A=L _D, $C_{4A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;{:L}_D},$ $L_{4B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_D},$ C _4B=C _D

Wherein: L _DBe inductance value in the low pass filter, C _DBe capacitance in the low pass filter, C _4BBe the capacitance of parallel branch after the equivalence, L _4BBe the inductance value of parallel branch after the equivalence,

In above 4 types of equivalence principles, ω ₀Be the central angle frequency of Design of Bandpass, i.e. ω ₀=π f ₀, f ₀Centered by frequency, 1090MHz as centre frequency, and is carried out equivalent substitution according to the low pass filter result who calculates in the step 2 according to above 4 kinds of principles and draws required band pass filter;

4. the path central spot at the band pass filter that designs loads the high speed tunnel diode, impact by actual measurement diode pair filter is effectively adjusted, when frequency of occurrences central point drifts about, adjust the size of by-pass inductor and path capacitance value, the adjustment amount of each inductance is not more than 1pH, the adjustment amount of each electric capacity is not more than 0.001pF, when the bandwidth variation occurring, adjust the size of shunt capacitance and path inductance value, the adjustment amount of each inductance is not more than 1nH, and the adjustment amount of each inductance is not more than 1pF.

The invention has the beneficial effects as follows: because the constant-K filter model is improved, the high speed tunnel diode is loaded in the path of filter model, by whole filter effect is carried out Measurement and analysis, matching value according to inductance and electric capacity in the filter of filter effect analysis and regulation dead band, reach the efficient filtering to the 1090MHz Frequency point, can effectively solve the aviation management signal is difficult to remove little noise interferences in reception ﹠ disposal technical problem.

Description of drawings

Fig. 1 is a kind of aviation management signal of the present invention dead band filter design method flow chart;

Fig. 2 is the low-pass filter circuit design principle figure in the filter design method specific embodiment of a kind of aviation management signal of the present invention dead band;

Fig. 3 is the filter circuit schematic diagram with the dead band in the filter design method specific embodiment of a kind of aviation management signal of the present invention dead band;

Fig. 4 is the frequency response curve of dead band filter in the filter design method specific embodiment of a kind of aviation management signal of the present invention dead band;

Fig. 5 is the simulation comparison figure of filter effect in the filter design method specific embodiment of a kind of aviation management signal of the present invention dead band.

Embodiment

With reference to accompanying drawing 1, accompanying drawing 2, accompanying drawing 3, accompanying drawing 4, accompanying drawing 5.

1. choose 1090MHz as the centre frequency of design of filter, adopt band bandwidth to be not more than 6MHz, impedance is the design standard of 50 Ω, and choosing input respectively is 50 Ω with output impedance, and deciding K type normalization low pass filter design data with reference to high-order (is that impedance is that 1 Ω and cut-off frequency are

Approximate 0.159Hz) as reference filter, wherein the high-order constant-K filter can be composed in series by resolving into several 2 rank basic model low pass filters that are comprised of the series connection of 1H inductance and 1F Capacitance parallel connection ground connection;

2. choose the minimum exponent number low pass filter that meets the demands as design basis, design normalization low pass filter passes through following formula

$L_{\left(\mathrm{MID}\right)}=\frac{L_{\left(\mathrm{OLD}\right)}}{M}$

$C_{\left(\mathrm{MID}\right)}=\frac{C_{\left(\mathrm{OLD}\right)}}{M}$

Wherein: L _(OLD)Be the size of the inductance in the reference filter of choosing, C _(OLD)Be the capacitance size in the reference filter of choosing;

Calculate the cut-off frequency conversion, and carry out the characteristic impedance conversion by following formula

L _(NEW)=L _(MID)×K

$C_{\left(\mathrm{NEW}\right)}=\frac{C_{\left(\mathrm{MID}\right)}}{K}$

Wherein: L _(NEW)Be the size of the inductance in the low pass filter that designs, C _(NEW)Be the capacitance size in the low pass filter that designs, K is 50; In the situation that do not change the wherein inductance value L through calculating of reference filter structure _(NEW)With capacitance C _(NEW)Replace with the fiducial value of original filter reference design, become the low pass filter with design band bandwidth, the result as shown in Figure 2;

3. utilize the band pass filter that K type normalization low pass filter data are come designing requirement of deciding that step 2 calculates, according to following circuit equivalent rule:

(1) uses capacitor C ₁With inductance L ₁Former path or the shunt capacitance C of replacing in parallel _A

$L_1=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_A},$ C ₁=C _A

Wherein: C _ABe capacitance in the low pass filter, L ₁Be the inductance value after the equivalence, C ₁Be the capacitance after the equivalence, (2) use capacitor C ₂With inductance L ₂Former path or by-pass inductor L are replaced in series connection _B

${\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002384810000022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_B},$ L ₂=L _B

Wherein: L _BBe inductance value in the low pass filter, C ₂Be the capacitance after the equivalence, L ₂Be the inductance value after the equivalence,

(3) use capacitor C _3AWith inductance L _3ASeries connection, inductance L _3B, capacitor C _3BThree tunnel former path or the by-pass inductor L of replacing in parallel _CWith capacitor C _CIn parallel

L _3A=L _C， $C_{3A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_C},$ $L_{3B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_C},$ C _3B=C _C

Wherein: L _CBe inductance value in the low pass filter, C _CBe capacitance in the low pass filter, L _3ABe the inductance value in the series arm after the equivalence, C _3ABe the capacitance in the series arm after the equivalence, C _3BBe the capacitance after the equivalence, L _3BBe the inductance value after the equivalence,

(4) use inductance L _4A, capacitor C _4AAnd inductance L _4BWith capacitor C _4BSeries connection replaces inductance L after in parallel _DWith capacitor C _DSeries connection L _4A=L _D, $C_{4A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;{:L}_D},$ $L_{4B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_D},$ C _4B=C _D

Wherein: L _DBe inductance value in the low pass filter, C _DBe capacitance in the low pass filter, C _4BBe the capacitance of parallel branch after the equivalence, L _4BBe the inductance value of parallel branch after the equivalence,

In above 4 types of equivalence principles, ω ₀Be the central angle frequency of Design of Bandpass, i.e. ω ₀=π f ₀, f ₀Centered by frequency, 1090MHz as centre frequency, and is carried out equivalent substitution according to the low pass filter result who calculates in the step 2 according to above 4 kinds of principles and draws required band pass filter;

4. the path central spot loading model at the band pass filter that designs is the high speed tunnel diode (as shown in Figure 3) of ZC137, impact by actual measurement diode pair filter is effectively adjusted, when frequency of occurrences central point drifts about, adjust the size of by-pass inductor and path capacitance value, the adjustment amount of each inductance is not more than 1pH, the adjustment amount of each electric capacity is not more than 0.001pF, when the bandwidth variation occurring, adjust the size of shunt capacitance and path inductance value, the adjustment amount of each inductance is not more than 1nH, the adjustment amount of each inductance is not more than 1pF, frequency response curve after the adjustment as shown in Figure 4, reached the effect of removing the medium and small noise interferences of aviation management signal, the simulated effect comparison diagram of the dead band filter that the present embodiment is designed as shown in Figure 5.

Claims (1)

1. aviation management signal dead band filter design method is characterized in may further comprise the steps:

(1) chooses 1090MHz as the centre frequency of design of filter, adopt band bandwidth to be not more than 6MHz, impedance is the design standard of 50 Ω, and choosing input respectively is 50 Ω with output impedance, and deciding K type normalization low pass filter design data with reference to high-order (is that impedance is that 1 Ω and cut-off frequency are

Approximate 0.159Hz) as reference filter, wherein the high-order constant-K filter can be composed in series by resolving into several 2 rank basic model low pass filters that are comprised of the series connection of 1H inductance and 1F Capacitance parallel connection ground connection;

(2) choose the minimum exponent number low pass filter that meets the demands as design basis, design normalization low pass filter passes through following formula

$L_{\left(\mathrm{MID}\right)}=\frac{L_{\left(\mathrm{OLD}\right)}}{M}$

$C_{\left(\mathrm{MID}\right)}=\frac{C_{\left(\mathrm{OLD}\right)}}{M}$

Wherein: L _(OLD)Be the size of the inductance in the reference filter of choosing, C _(OLD)Be the capacitance size in the reference filter of choosing;

Calculate the cut-off frequency conversion, and carry out the characteristic impedance conversion by following formula

L _(NEW)＝L _(MID)×K

$C_{\left(\mathrm{NEW}\right)}=\frac{C_{\left(\mathrm{MID}\right)}}{K}$

Wherein: L _(NEW)Be the size of the inductance in the low pass filter that designs, C _(NEW)Be the capacitance size in the low pass filter that designs, K is 50;

In the situation that do not change the wherein inductance value L through calculating of reference filter structure _(NEW)With capacitance C _(NEW)Replace with the fiducial value of original filter reference design, become the low pass filter with design band bandwidth;

(3) utilize the band pass filter that K type normalization low pass filter data are come designing requirement of deciding that step 2 calculates, according to following circuit equivalent rule:

(a) use capacitor C ₁With inductance L ₁Former path or the shunt capacitance C of replacing in parallel _A

$L_1=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_A},$ C ₁=C _A

Wherein: C _ABe capacitance in the low pass filter, L ₁Be the inductance value after the equivalence, C ₁Be the capacitance after the equivalence, (b) use capacitor C ₂With inductance L ₂Former path or by-pass inductor L are replaced in series connection _B

$C_2=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_B},$ L ₂=L _B

Wherein: L _BBe inductance value in the low pass filter, C ₂Be the capacitance after the equivalence, L ₂Be the inductance value after the equivalence,

(c) use capacitor C _3AWith inductance L _3ASeries connection, inductance L _3B, capacitor C _3BThree tunnel former path or the by-pass inductor L of replacing in parallel _CWith capacitor C _CL3A=L in parallel _C, $C_{3A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;L_C},$ $L_{3B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_C},$ C _3B=C _C

Wherein: L _CBe inductance value in the low pass filter, C _CBe capacitance in the low pass filter, L _3ABe the inductance value in the series arm after the equivalence, C _3ABe the capacitance in the series arm after the equivalence, C _3BBe the capacitance after the equivalence, L _3BBe the inductance value after the equivalence,

(d) use inductance L _4A, capacitor C _4AAnd inductance L _4BWith capacitor C _4BSeries connection replaces inductance L after in parallel _DWith capacitor C _DSeries connection L _4A=L _D, $C_{4A}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;{:L}_D},$ $L_{4B}=\frac{1}{{{\mathrm{\&omega;}}_0}^2\&CenterDot;C_D},$ C _4B=C _D

Wherein: L _DBe inductance value in the low pass filter, C _DBe capacitance in the low pass filter, C _4BBe the capacitance of parallel branch after the equivalence, L _4BBe the inductance value of parallel branch after the equivalence,

In above 4 types of equivalence principles, ω ₀Be the central angle frequency of Design of Bandpass, i.e. ω ₀=π f ₀, f ₀Centered by frequency, 1090MHz as centre frequency, and is carried out equivalent substitution according to the low pass filter result who calculates in the step 2 according to above 4 kinds of principles and draws required band pass filter;

(4) the path central spot at the band pass filter that designs loads the high speed tunnel diode, impact by actual measurement diode pair filter is effectively adjusted, when frequency of occurrences central point drifts about, adjust the size of by-pass inductor and path capacitance value, the adjustment amount of each inductance is not more than 1pH, the adjustment amount of each electric capacity is not more than 0.001pF, when the bandwidth variation occurring, adjust the size of shunt capacitance and path inductance value, the adjustment amount of each inductance is not more than 1nH, and the adjustment amount of each inductance is not more than 1pF.

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