CN204668440U - Lumped parameter quadrature bridge - Google Patents

Abstract

The utility model relates to a kind of lumped parameter quadrature bridge, comprise coaxial line, coupling capacitance, printed circuit board, the inner wire of the every one end of described coaxial line is all connected by described coupling capacitance with outer conductor, and described coaxial line, described coupling capacitance are all welded on a printed circuit board.The utility model has the advantage of filter with low insertion loss, low port standing wave, the low amplitude degree of balance and phase balance, high-isolation, high power capacity, and its volume is little, cost is low, circuit is simple, it is good to make consistency, debugging is simple, be convenient to produce in enormous quantities, the application scenario, arrowband being less than 25% in the low-frequency range of VHF, bandwidth especially has better advantage.

Description

Lumped parameter quadrature bridge

Technical field

The utility model relates to quadrature bridge technical field, particularly relates to a kind of lumped parameter quadrature bridge.

Background technology

At VHF (Very High Frequency, very high frequency(VHF)) radio frequency band, quadrature bridge generally has microstrip line distributed constant and inductance capacitance lumped parameter two kinds of ways of realization.Its frequency of microstrip line distributed constant quadrature bridge is low, wavelength is very long, and cause volume too large, cost is high, and power capacity is not high.The simplest structure of lumped parameter quadrature bridge as shown in Figure 1, be made up of a mutual inductor and two electric capacity, divide equally and phase 90 degree, and mutual inductor is twisted together by two enamelled wires by two output port signal powers, ensures coupling coefficient adopt the lumped parameter quadrature bridge of rope-lay conductor structure to effectively reduce volume, but be difficult to ensure consistency by the mutual inductor coupling coefficient of two enamelled wire twistings, the coiling consistency of mutual inductor is poor, is unfavorable for batch production, and limited power capacity.

Utility model content

Based on this, for solving quadrature bridge Problems existing in prior art, the utility model provides a kind of lumped parameter quadrature bridge, and this quadrature bridge has high power capacity, and volume is little, cost is low, and debugging is simple, makes consistency good, is convenient to produce in enormous quantities.

For achieving the above object, the utility model adopts following technical scheme in an embodiment:

A kind of lumped parameter quadrature bridge, comprise coaxial line, coupling capacitance, printed circuit board, the inner wire of the every one end of described coaxial line is all connected by described coupling capacitance with outer conductor, and described coaxial line, described coupling capacitance are all welded on a printed circuit board.

Preferably, described coaxial line coiling is circular or rectangle.

Further, the lumped parameter quadrature bridge in the utility model embodiment also comprises self-induction coil, ground capacity; Inner wire and the outer conductor of the every one end of described coaxial line are connected to the two ends of described coupling capacitance respectively by described self-induction coil, and the two ends of described coupling capacitance are also by described ground capacity ground connection.The lumped parameter quadrature bridge of this version has bandwidth, advantage that amplitude balance is good.

Further, for suppressing high-frequency noise, the lumped parameter quadrature bridge in the utility model embodiment also comprises magnet ring, and described coaxial line is wound on described magnet ring, reduces noise jamming with this.

The utility model adopts coaxial line as mutual inductor, and the inner wire of coaxial line and outer conductor are equivalent to two rope-lay conductors, have close coupling between the inner wire of coaxial line and outer conductor, can well realize the straight-through of power and coupling distribution.The lumped parameter quadrature bridge that the utility model provides has the advantage of filter with low insertion loss, low port standing wave, the low amplitude degree of balance and phase balance, high-isolation, high power capacity, and its volume is little, cost is low, circuit is simple, it is good to make consistency, debugging is simple, be convenient to produce in enormous quantities, the application scenario, arrowband being less than 25% in the low-frequency range of VHF, bandwidth especially has better advantage.

Accompanying drawing explanation

Fig. 1 is the circuit theory schematic diagram of lumped parameter quadrature bridge in prior art;

Fig. 2 is the lumped parameter quadrature bridge schematic diagram in the utility model embodiment one;

Fig. 3 is the circuit theory schematic diagram of lumped parameter quadrature bridge in the utility model embodiment two.

Embodiment

Below in conjunction with accompanying drawing, particular content of the present utility model is described further.

Embodiment one

Fig. 2 is the schematic diagram of the lumped parameter quadrature bridge in the utility model embodiment one, and as shown in Figure 2, this lumped parameter quadrature bridge comprises coaxial line 1, coupling capacitance 2, printed circuit board 3.The inner wire of the every one end of coaxial line 2 is all connected by coupling capacitance 2 with outer conductor, and coaxial line 1, coupling capacitance 2 are all welded on printed circuit board 3.Wherein, coupling capacitance 2 can adopt high q-factor, high-voltage capacitance.The size of printed circuit board (pcb board) can rationally be arranged according to demand, is to ensure the less volume of quadrature bridge, and whole pcb board size can be designed to that length is no more than 40 millimeters, width is no more than 15 millimeters, is highly no more than 15 millimeters.

Core of the present utility model is to use coaxial line 1 as mutual inductor, and coaxial line is common signal transmssion line, and coaxial line ecto-entad is sheath, outer conductor (screen), dielectric and inner wire 4 part successively.Wherein sheath is the outmost insulating barrier of coaxial line, mainly shields; Outer conductor (screen) has double action, and it is both as a wire in transmission loop, and transmission low level, has shielding action again; Dielectric mainly improves interference free performance, the erosion such as anti-sealing, oxygen simultaneously; Inner wire is for transmitting high level, and its main material is generally copper.Based on the special construction of coaxial line, the inner wire of coaxial line and outer conductor can be equivalent to two rope-lay conductors, and have close coupling between the inner wire of coaxial line and outer conductor, can well realize the straight-through of power and coupling distribution.

In the present embodiment one, use coaxial line (semihard preferably can shaped or the half soft coaxial line of certain length, guaranteed performance is reliable and stable), circle is coiled into according to certain diameter specifications, also rectangle or other shapes can be coiled into, ensure certain inductance value, wherein inductance value, capacitance are by following formulae discovery:

$L=\frac{R}{2\sqrt{2}\mathrm{\π}f},C=\frac{1}{2\sqrt{2}\mathrm{\π}f\text{R}}$

Wherein, the unit of L, C, R, f is international unit processed.

The power capacity of quadrature bridge depends primarily on the withstand voltage of coaxial line medium withstand voltage and coupling capacitance, therefore selects the coupling capacitance of the coaxial line of general requirements and large encapsulation can meet the requirement of quadrature bridge power capacity.

In addition, the size of quadrature bridge power capacity is also relevant with the Insertion Loss of quadrature bridge, especially under kilowatt order of magnitude or higher power.Its Insertion Loss of lumped parameter quadrature bridge in the present embodiment one is little, and when relatively high power, the power of quadrature bridge loss is little, can steady operation.And for adopting the quadrature bridge of enamelled wire twisted configuration in prior art, heat accumulates in a large number under continuous operation condition, be difficult to the reliability ensureing its work.

In the size of coaxial line, can adjust according to design needs, only need to make coaxial line meet inductance value requirement, when length increases, inductance coil diameter can be reduced, increase the number of turns, therefore there is very strong flexibility in design.

A kind of lumped parameter quadrature bridge of the present embodiment an additional metal structure and 4 can also be connected to SMA or the N-type radio frequency head of port, makes independent device and uses, directly can certainly be distributed on pcb board and use.

Below the lumped parameter quadrature bridge in the present embodiment one is emulated, to verify its beneficial effect.

Lumped parameter right bridge for emulating in the present embodiment one, wherein printed circuit board 3 length, width and height are respectively 45 × 15 × 15 millimeters; Centre frequency 45MHz; The length of coaxial line 1 is 310 millimeters; Coupling capacitance is 28pF; Find after emulation, Insertion Loss is less than 0.15dB, ensures that the power of the quadrature bridge loss when relatively high power works is also little; Each port standing wave is less than 1.25dB, ensures that quadrature bridge influences each other very little when being connected with other devices; Isolation between port is greater than 25dB, shows to influence each other between port also less; In addition, amplitude balance is less than ± 0.4dB, and phase balance is less than ± and 5 °, effective relative bandwidth is greater than 25%, and performance index are excellent.

Embodiment two

The present embodiment two provides a kind of lumped parameter quadrature bridge, comprises coaxial line, coupling capacitance, printed circuit board, also comprises self-induction coil and ground capacity.Inner wire and the outer conductor of the every one end of coaxial line are connected to the two ends of coupling capacitance respectively by self-induction coil, and the two ends of coupling capacitance are also by ground capacity ground connection.

Fig. 3 is the circuit theory diagrams of lumped parameter quadrature bridge in the present embodiment two.As shown in Figure 3, mutual inductor L1 is formed by coaxial line coiling, the two ends symmetrically structure of mutual inductor L1, and every one end is all connected to the two ends of coupling capacitance C1 by two self-induction coil L2, and the two ends of coupling capacitance C1 are all by ground connection after ground capacity C2.Wherein, coupling capacitance C1 can adopt high q-factor, high-voltage capacitance.

Use the coaxial line of certain length, be coiled into mutual inductor L1 according to certain diameter specifications, can coiling be specifically circle, rectangle or other shapes, ensure certain inductance value, coaxial line preferably adopts the semihard or half soft coaxial line that can shape, ensures that mutual inductor is stable and reliable for performance.

The power capacity of quadrature bridge depends primarily on the withstand voltage of coaxial line medium withstand voltage and coupling capacitance, therefore selects the coupling capacitance of the coaxial line of general requirements and large encapsulation can meet the requirement of quadrature bridge power capacity.In the size of coaxial line, can adjust according to design needs, only need to make coaxial line meet inductance value requirement, when length increases, inductance coil diameter can be reduced, increase the number of turns, therefore there is very strong flexibility in design.

Compared to embodiment one, lumped parameter quadrature bridge in the present embodiment two introduces self-induction coil, ground capacity, although circuit structure, debugging efforts are more more complex than the lumped parameter quadrature bridge in embodiment one, but it has bandwidth, advantage that amplitude balance is good, also can be used widely at VHF radio frequency band.

Further, the lumped parameter quadrature bridge in the utility model also can comprise magnet ring, is wound on by coaxial line on magnet ring, effectively can reduce noise jamming.Although can produce power loss after introducing magnet ring, can suppress high-frequency noise when quadrature bridge power is less, therefore this kind of structure also has certain using value.

Comprehensive foregoing, the utility model adopts coaxial line as mutual inductor, the inner wire of coaxial line and outer conductor are equivalent to two rope-lay conductors, between the inner wire of coaxial line and outer conductor, there is close coupling, the straight-through of power and coupling distribution can well be realized.The utility model has the advantage of filter with low insertion loss, low port standing wave, the low amplitude degree of balance and phase balance, high-isolation, high power capacity, and its volume is little, cost is low, circuit is simple, it is good to make consistency, debugging is simple, be convenient to produce in enormous quantities, the application scenario, arrowband being less than 25% in the low-frequency range of VHF, bandwidth especially has better advantage.

Each technical characteristic of the above embodiment can combine arbitrarily, for making description succinct, the all possible combination of each technical characteristic in above-described embodiment is not all described, but, as long as the combination of these technical characteristics does not exist contradiction, be all considered to be the scope that this specification is recorded.

The above embodiment only have expressed several execution mode of the present utility model, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to utility model patent scope.It should be pointed out that for the person of ordinary skill of the art, without departing from the concept of the premise utility, can also make some distortion and improvement, these all belong to protection range of the present utility model.Therefore, the protection range of the utility model patent should be as the criterion with claims.

Claims (4)

1. a lumped parameter quadrature bridge, it is characterized in that, comprise coaxial line, coupling capacitance, printed circuit board, the inner wire of the every one end of described coaxial line is all connected by described coupling capacitance with outer conductor, and described coaxial line, described coupling capacitance are all welded on a printed circuit board.

2. lumped parameter quadrature bridge according to claim 1, is characterized in that, described coaxial line coiling is circular or rectangle.

3. lumped parameter quadrature bridge according to claim 1 and 2, is characterized in that, also comprises self-induction coil, ground capacity; Inner wire and the outer conductor of the every one end of described coaxial line are connected to the two ends of described coupling capacitance respectively by described self-induction coil, and the two ends of described coupling capacitance are also by described ground capacity ground connection.

4. lumped parameter quadrature bridge according to claim 1 and 2, is characterized in that, also comprise magnet ring, and described coaxial line is wound on described magnet ring.