CN201656919U

CN201656919U - Integrated filter

Info

Publication number: CN201656919U
Application number: CN2009201045339U
Authority: CN
Inventors: 郑升灵; 李宏军; 李明武; 杨亮
Original assignee: BOWEI INTEGRATED CIRCUITS Co Ltd
Current assignee: BOWEI INTEGRATED CIRCUITS Co Ltd
Priority date: 2009-09-18
Filing date: 2009-09-18
Publication date: 2010-11-24
Anticipated expiration: 2019-09-18

Abstract

The utility model discloses an integrated filter, including a filter and a phase compensating circuit, wherein the input terminal of the phase compensating circuit is connected to the output terminal of the filter. The utility model adds a phase compensating circuit to the filter, so that the filter has features of small pass band delay fluctuation, better selection characteristic, convenient circuit debugging, easy realization, strong engineering practicability, and convenient batch production. The standing wave in the pass band can achieve 1.5 or below, is suitable for situation having rigorous requirement to both amplitude-frequency characteristic and phase frequency characteristic, and is specially a suitable for broad band filtering and trans octave filtering situation. dapted ternal, to of popple, by s, but also the phase compensation circuit, the phase compensation circuit input termination output filter, the new filter to increase by a phase compensation circuit, the filter has small fluctuations in the passband delay, select the features better, circuit debugging convenient, easy to implement, engineering practicality, ease of mass production and production characteristics, and its pass-band standing wave can reach below 1.5 for amplitude-frequency characteristics and phase frequency where requirements are very strict, especially for cross-octave bandwidth filter and filter applications.

Description

Integrated filter

Technical field

The utility model relates to a kind of filter, especially a kind of integrated filter with phase compensating network.

Background technology

Along with group (portion) part, machine system performance upgrade, the phase place index of filter is had higher requirement.Under the situation about outside requiring high-band, suppressing, phase linearity in the filter passband has been proposed simultaneously, to guarantee signal distortionless output behind the process filter.Existing wave filter technology generally adopt the filter of linear phase function Bezier type or Gaussian, but such filter exists attenuation outside a channel slow, and the passband standing internal wave is poor, and filter circuit is asymmetric, and component value is discrete, and difficulty is big in the engineering debug.Therefore, for satisfying the high performance requirements of system equipment to filter, we must adopt new thinking and select new circuit structure, thereby realize the new mode filter of high squareness factor, flat time-delay.

The utility model content

The utility model technical issues that need to address provide the flat time-delay characteristics of a kind of existing Bezier or Gaussian filter, and the integrated filter of high squareness factor and little passband standing wave is arranged again.

For addressing the above problem, technical solution adopted in the utility model is: a kind of integrated filter, comprise filter, and also comprise phase compensating circuit, the output of the input termination filter of its phase compensating circuit.

Described filter is chebyshev function filter or elliptic function filter.

Described phase compensating circuit is a joint T type all-pass network, comprises capacitor C 1-C3, inductance L 1, L2, and wherein capacitor C 1 and C3 series connection back and capacitor C 2, inductance L 1 are in parallel, and the other end is an output signal, and the node of capacitor C 1 and C3 passes through inductance L 2 ground connection.

Described phase compensating circuit is the equalizing network of four joint series connection, wherein first segment comprises capacitor C 1, C2, transformer T1, the two ends of capacitor C 1 connect the primary coil of transformer T1, an end of secondary coil respectively, one termination filter, another termination second joint input, the primary coil of transformer T1, the other end of secondary coil are by capacitor C 2 ground connection; Second joint comprises capacitor C 11-C14, inductance L 11, L12, and capacitor C 11 and C13 series connection back and capacitor C 12, inductance L 11 are in parallel, another termination the 3rd joint, the node of capacitor C 11 and C13 passes through inductance L 12, capacitor C 14 ground connection successively; The 3rd joint comprises capacitor C 21-C23, inductance L 21, L22, and wherein capacitor C 21 and C22 series connection back and inductance L 21 backs in parallel one termination second save output, another termination the 4th joint, the node of capacitor C 21 and C22 is successively by inductance L 22, capacitor C 23 ground connection; Capacitor C 31-C33, inductance L 31, L32, wherein capacitor C 31 and C33 series connection back and capacitor C 32, inductance L 31 are in parallel, and the other end is an output signal, and the node of capacitor C 31 and C33 passes through inductance L 32 ground connection.

Adopt the beneficial effect that technique scheme produced to be: this is novel by increasing phase compensating circuit to filter, make filter have that passband time-delay fluctuation is little, selectivity characteristic is better, circuit debugging is convenient, be easy to realize, engineering practicability is strong, is convenient to the characteristics of batch making and production, and its passband standing internal wave can reach below 1.5, be applicable to that amplitude-frequency characteristic and phase-frequency characteristic require all very strict occasion, be specially adapted to wideband filtered and the occasion of striding octave filtering.

Description of drawings

Fig. 1 is the utility model structural representation;

Fig. 2 is a kind of circuit diagram of the utility model phase compensating circuit;

Fig. 3 is the another kind of circuit diagram of the utility model phase compensating circuit;

Embodiment

Below in conjunction with accompanying drawing the utility model is done and to be described in further detail:

As shown in Figure 1, this is novel mainly to be made of the chebyshev function of high rectangle or elliptic function filter and phase compensating circuit two parts, the input of the output termination phase compensating circuit of filter, its median filter adopts filters such as chebyshev function or elliptic function, revise the time-delay acute variation of former filter filtering circuit passband side frequency by the anti-fitting duration curve of compensating circuit, reach the time-delay fluctuation that improves in the filter passband, phase compensating circuit is a kind of delay equalization all-pass network that hinders surely, the group delay characteristic of filter filtering circuit is greatly improved in its introducing, form the passband convex curve at a time delay peak at the centre frequency place, superpose with the passband sag vertical curve of first electronic circuit filter again and reach and improve the time delay fluctuation, and because the all-pass network port is easy to coupling, the amplitude-frequency pass-band loss is less, does not influence the amplitude characteristic of filter after the cascade substantially.

As shown in Figure 2, a kind of phase compensating circuit is a joint T type all-pass network, comprises capacitor C 1-C3, inductance L 1, L2, wherein capacitor C 1 and C3 series connection back and capacitor C 2, inductance L 1 are in parallel, and the other end is an output signal, and the node of capacitor C 1 and C3 passes through inductance L 2 ground connection.

As shown in Figure 3, another kind of phase compensating circuit is the equalizing network of four joint series connection, wherein first segment comprises capacitor C 1, C2, transformer T1, the two ends of capacitor C 1 connect the primary coil of transformer T1, an end of secondary coil respectively, one termination filter, another termination second joint input, the primary coil of transformer T1, the other end of secondary coil are by capacitor C 2 ground connection; Second joint comprises capacitor C 11-C14, inductance L 11, L12, and wherein capacitor C 11 and C13 series connection back and capacitor C 12, inductance L 11 are in parallel, another termination the 3rd joint, the node of capacitor C 11 and C13 passes through inductance L 12, capacitor C 14 ground connection successively; The 3rd joint comprises capacitor C 21-C23, inductance L 21, L22, and wherein capacitor C 21 and C22 series connection back and inductance L 21 backs in parallel one termination second save output, another termination the 4th joint, the node of capacitor C 21 and C22 is successively by inductance L 22, capacitor C 23 ground connection; Capacitor C 31-C33, inductance L 31, L32, wherein capacitor C 31 and C33 series connection back and capacitor C 32, inductance L 31 are in parallel, and the other end is an output signal, and the node of capacitor C 31 and C33 passes through inductance L 32 ground connection.

Embodiment one

The present embodiment median filter adopts 6 joint chebyshev functions, filter circuit adopts centre frequency 200M, the filter of bandwidth 20M, phase compensating circuit adopts circuit shown in Figure 2, be that phase compensating circuit is selected a joint T type all-pass network for use, its test result shows: in the band time-delay fluctuation little, drop to behind the connection phase compensating circuit about 10ns by the about 30ns of independent filter; Selectivity is preferably arranged, squareness factor K40/3≤2.2.

Embodiment two

Comprise filter and phase compensating circuit in the present embodiment.Be that with last routine difference filter is the broadband elliptic filter, the compensating circuit structure that is adopted is also different with joint number, and this routine compensating circuit is selected four joint equalizing networks for use.Its test result shows: in the band time-delay fluctuation little, dropped to about 12ns behind the connection phase compensating circuit by the about 85ns of independent filter; High selectivity is arranged, squareness factor K40/3≤1.5.

Claims

1. an integrated filter comprises filter, it is characterized in that: also comprise phase compensating circuit, the output of the input termination filter of its phase compensating circuit.

2. according to the described integrated filter of claim 1, it is characterized in that described filter is chebyshev function filter or elliptic function filter.

3. integrated filter according to claim 1, it is characterized in that described phase compensating circuit is a joint T type all-pass network, comprise capacitor C 1-C3, inductance L 1, L2, wherein capacitor C 1 and C3 series connection back and capacitor C 2, inductance L 1 are in parallel, the other end is an output signal, and the node of capacitor C 1 and C3 is by inductance L 2 ground connection.

4. integrated filter according to claim 1, it is characterized in that described phase compensating circuit is the equalizing network of four joint series connection, wherein first segment comprises capacitor C 1, C2, transformer T1, the two ends of capacitor C 1 connect the primary coil of transformer T1, an end of secondary coil respectively, one termination filter, another termination second joint input, the primary coil of transformer T1, the other end of secondary coil are by capacitor C 2 ground connection; Second joint comprises capacitor C 11-C14, inductance L 11, L12, and capacitor C 11 and C13 series connection back and capacitor C 12, inductance L 11 are in parallel, another termination the 3rd joint, the node of capacitor C 11 and C13 passes through inductance L 12, capacitor C 14 ground connection successively; The 3rd joint comprises capacitor C 21-C23, inductance L 21, L22, and wherein capacitor C 21 and C22 series connection back and inductance L 21 backs in parallel one termination second save output, another termination the 4th joint, the node of capacitor C 21 and C22 is successively by inductance L 22, capacitor C 23 ground connection; Capacitor C 31-C33, inductance L 31, L32, wherein capacitor C 31 and C33 series connection back and capacitor C 32, inductance L 31 are in parallel, and the other end is an output signal, and the node of capacitor C 31 and C33 passes through inductance L 32 ground connection.