CN103346373B - Coupler is spent in a kind of broadband 180 of lumped parameter - Google Patents

Abstract

Coupler is spent in the broadband 180 that the present invention relates to a kind of lumped parameter, comprises four electric capacity and four inductance, and wherein, four electric capacity and three inductance connect and compose double loop; Another inductance one termination the 3rd tie point, one end ground connection, form inductive coupled, in order to improve the bandwidth of operation of coupler; The first tie point connects the first port; The second tie point connects the second port; The 4th tie point connects the 3rd port. Coupler is spent in lumped parameter of the present invention broadband 180, it uses element few, and area occupied is little, realizes cost low, can in the frequency band range of non-constant width, keep the good output amplitude degree of balance and phase balance, be applicable in current hand-held mobile Radio-Frequency Wireless Communication system.

Description

Coupler is spent in a kind of broadband 180 of lumped parameter

Technical field

The present invention relates to communication circuit elements technical field, particularly relate to a kind of broadband 180 degree couplings of lumped parameterDevice.

Background technology

In Modern Communication System, in radio frequency and microwave and millimeter wave circuit, as balance amplifier, mirror image suppresses mixingDevice, in balanced type frequency multiplier etc., usually needs to use 180 degree couplers. Especially at current mobile electron Communications MarketIn, along with the development of multifrequency (multi-band) multimode (multi-mode) technology, can meet various frequency ranges and communication simultaneouslyThe radio frequency transceiver of standard becomes current developing direction. As device important in receive-transmit system, the 180 degree couplings in broadbandThe demand of device is just constantly strengthened. At present popular 180 traditional degree couplers adopt microstrip structure mostly, as Marchand barHuman relations, 180 micro-band hybrid rings, Lange coupler to etc. These microstrip structures 180 based on electrical length are spent coupler at radio frequencyArea shared in band limits is very large, has greatly increased area and the cost of radio system. Recently, some are based on lump180 degree couplers of components and parts are reported to some extent in periodical, as " Compact28-GHzsubharmonicallypumpedresistivemixerMMICusingalumped-elementhigh-pass/band-passbalun,”IEEEMicrow.WirelessCompon.Lett., vol.15, no.2, pp.62-64, Feb.2005 and " Designofcompact90oand180ocouplerswithharmonicsuppressionusinglumped-elementbandstopresonators,”IEEETrans.Microw.TheoryTech.,vol.58,no.11,pp.2932-2939, Nov.2010. still these circuit can only provide very narrow frequency bandwidth (being less than 10%), thereby has greatly limited itApplication, especially at current GSM.

Summary of the invention

Coupler is spent in the broadband 180 that the invention provides a kind of lumped parameter, and it uses number of devices few, and area occupied is little,And there is wider working band, spend thereby solved current broadband 180 skill that coupler area occupied is large and price is highArt problem, the while has also solved the problem of 180 degree coupler bandwidth deficiencies of lumped device.

The technical solution adopted for the present invention to solve the technical problems is: provide a kind of broadband 180 of lumped parameter to spend couplingClose device, comprise four electric capacity and three inductance, four electric capacity are respectively the first electric capacity, the second electric capacity, the 3rd electric capacity and the 4th electricityHold, three inductance are respectively the first inductance, the second inductance and the 3rd inductance, one of one end of described the first inductance and the first electric capacityEnd is all connected in the first tie point; One end of the other end of described the first inductance and the second electric capacity is all connected in the second tie point;One end of one end of the other end of described the second electric capacity, one end of the second inductance and the 3rd electric capacity is all connected in the 3rd tie point;One end of the other end of described the 3rd electric capacity and the 3rd inductance is connected in the 4th tie point; The other end of described the 3rd inductance andOne end of four electric capacity is connected in the 5th tie point; The other end of described the first electric capacity, the other end of the second inductance and the 4th electric capacityThe other end be connected in the 6th tie point; Described the first tie point connects the first port; Described the second tie point connects the second endMouthful; Described the 3rd tie point is connected with earth terminal; Described the 4th tie point connects the 3rd port.

Between described the 3rd tie point and earth terminal, be also connected with the 4th inductance.

Described the first electric capacity, the second electric capacity, the 3rd electric capacity and the 4th electric capacity have identical capacitance.

Described the first inductance and the 3rd inductance have identical inductance value.

The inductance value of described the second inductance is the half of the inductance value of the first inductance.

The inductance value of described the 4th inductance is the 1/n of the inductance value of the first inductance, and wherein, n is proportionality constant.

Described proportionality constant is between 0.1 to 0.2.

The capacitance of described the first electric capacity, the second electric capacity, the 3rd electric capacity and the 4th electric capacity isItsIn, Z_inFor the impedance of system input mouth, Z_outFor the impedance of system output port, ω is operating frequency.

The inductance value of described the first inductance and the 3rd inductance isWherein, Z_inFor the resistance of system input mouthAnti-, Z_outFor the impedance of system output port, ω is operating frequency.

Beneficial effect

Owing to having adopted above-mentioned technical scheme, the present invention compared with prior art, has following advantage and actively imitatesReally: the present invention adopts lumped-parameter element, can greatly dwindle area and become than traditional micro-180 degree couplers of being withThis, spend coupler compared to traditional lumped parameter 180 and can improve greatly bandwidth of operation, thereby it is logical to meet wireless mobileThe miniaturization of communication system and the requirement of multiband.

Brief description of the drawings

Fig. 1 is that coupler circuit topological structure schematic diagram is spent in lumped parameter of the present invention broadband 180;

Fig. 2 is the strange mould topological structure schematic diagram that coupler circuit (one side of something) is spent in lumped parameter of the present invention broadband 180;

Fig. 3 is the even mould topological structure schematic diagram that coupler circuit (one side of something) is spent in lumped parameter of the present invention broadband 180;

Fig. 4 is the scattering parameter curve map that coupler circuit emulation is spent in lumped parameter of the present invention broadband 180;

Fig. 5 be lumped parameter of the present invention broadband 180 spend between the output port of coupler circuit emulation (the second port andThe 3rd port) the amplitude imbalance line chart of writing music;

Fig. 6 be lumped parameter of the present invention broadband 180 spend between the output port of coupler circuit emulation (the second port andThe 3rd port) phase unbalance degree curve map.

Detailed description of the invention

Below in conjunction with specific embodiment, further set forth the present invention. Should be understood that these embodiment are only for illustrating the present inventionLimit the scope of the invention and be not used in. In addition should be understood that after having read the content of the present invention's instruction art technology peopleMember can make various changes or modifications the present invention, and these equivalent form of values fall within equally the application's appended claims and limitScope.

A coupler is spent in the broadband 180 of lumped parameter, as shown in Figure 1, comprises four electric capacity and four inductance, respectivelyBe the first inductance L 1, the second inductance L 2, the 3rd inductance L 3, the 4th inductance L 4, the first capacitor C 1, the second capacitor C 2, the 3rd electric capacityC3 and the 4th capacitor C 4. Wherein, one end of one end of described the first inductance L 1 and the first capacitor C 1 is connected in the first tie point 01;One end of the other end of described the first inductance L 1 and the second capacitor C 2 is connected in the second tie point 02; Described the second capacitor C 2 anotherOne end of one end of one end, the second inductance L 2, one end of the 3rd capacitor C 3 and the 4th inductance L 4 is connected in the 3rd tie point 03; InstituteState the other end ground connection of the 4th inductance L 4; One end of the other end of described the 3rd capacitor C 3 and the 3rd inductance L 3 is connected in the 4th and connectsContact 04; One end of the other end of described the 3rd inductance L 3 and the 4th capacitor C 4 is connected in the 5th tie point 05; Described the first electricityThe other end, the other end of the second inductance L 2 and the other end of the 4th capacitor C 4 that hold C1 are connected in the 6th tie point 06; DescribedOne tie point 01 connects the first port one; Described the second tie point 02 connects the second port 2; Described the 4th tie point 04 connectsThree ports 3. Described the 4th inductance L 4 is connected across between the 3rd tie point 03 and ground, forms secondary inductive coupled, and raising work frequentlyBand bandwidth.

According to microwave network theory, adopt Even odd mode method to analyze circuit network topology as shown in Figure 1. Fig. 2 andFig. 3 represents respectively its strange mould and even moding circuit. Suppose that the first port is network input port, what the second port was network is straight-throughPort, the coupling port that the 3rd port is network, the isolated port that the 4th port is network. The scattering parameter square of parity mode circuitBattle array is respectively:

${\[S\]}_{odd}=\left[\begin{array}{cc}{S}_{11}^o& S_{21}^o\\ S_{12}^o& S_{22}^o\end{array}\right]---1)$

${\[S\]}_{even}=\left[\begin{array}{cc}{S}_{11}^e& S_{21}^e\\ S_{12}^e& S_{22}^e\end{array}\right]---2)$

WhereinRepresent that strange mould energy injects from j mouth, records energy at i mouth;Represent that even mould energy injects from j mouth, at iMouth records energy.Be expressed as strange mould signal from the energy of the first port one reflection and putting down of the first port one input energy ratioRoot;When being expressed as the second port 2 and mating, the forward transmission coefficient of strange mould signal from the first port one to the second port 2;While being expressed as the first port one coupling, strange mould signal is from the forward transmission coefficient of the second port 2 to first port ones;Be expressed asThe energy that strange mould signal reflects from the second port 2 and the second port 2 are inputted the square root of energy ratio;Be expressed as even mould signalFrom the energy of the first port one reflection and the square root of the first port one input energy ratio;Being expressed as the second port 2 matesTime, the forward transmission coefficient of even mould signal from the first port one to the second port 2;While being expressed as the first port one coupling, even mouldSignal is from the forward transmission coefficient of the second port 2 to first port ones;Be expressed as the energy that even mould signal reflects from the second port 2Amount and the second port 2 are inputted the square root of energy ratio.

Can be obtained the scattering parameter of directional coupler by network theory:

$S_{11}=\frac{1}{2}(S_{11}^e+S_{11}^o)---3)$

$S_{21}=\frac{1}{2}(S_{11}^e-S_{11}^o)---4)$

$S_{31}=\frac{1}{2}(S_{21}^e-S_{21}^o)---5)$

$S_{41}=\frac{1}{2}(S_{21}^e+S_{21}^o)---6)$

The parameter being optimized is:

$C=\frac{1}{\mathrm{\ω}\sqrt{2Z_{in}{Z}_{out}}}---7)$

$L=\frac{\sqrt{2Z_{in}{Z}_{out}}}{\mathrm{\ω}}---8)$

0.1＜n＜0.29)

Wherein, Z_inRepresent input port impedance, Z_outRepresent output port impedance, ω₀Represent coupler operating frequency. RatioExample constant n is between 0.1 and 0.2, and optimum value is in 0.15 left and right.

Suppose that input/output port is 50 ohmages, thus the bandwidth of operation being optimized (output insertion lossBe less than 1dB, between output port, phase difference departs from 180 degree and is less than 2 degree, and between output port, amplitude difference is less than 0.5dB) be greater than 50%,And traditional lumped parameter 180 is spent the bandwidth of operation of coupler and is less than 10%.

The first capacitor C 1, the second capacitor C 2, the 3rd capacitor C 3 and the 4th capacitor C 4 have identical capacitance; The first inductanceL1 and the 3rd inductance L 3 have identical inductance value; The inductance value of the second inductance L 2 is that the first inductance L 1 inductance value obtains half; TheThe inductance value of four inductance L 4 is 15% of the first inductance L 1. In the present embodiment, spend with the broadband 180 of the lumped parameter of 2.45GHzCoupler is example, but is not limited only to the 180 degree couplers of 2.45GHz. According to formula 7), 8) and 9), obtain above-mentioned each first deviceThe parameter value of part is selected as follows:

Device name	Device value
		C1	0.9pF
C2	0.9pF
		C3	0.9pF
C4	0.9pF
		L1	4.7nH
L2	4.7nH
		L3	2.3nH
L4	0.7nH

In the present embodiment, the first port one is input port, and the second port 2 is straight-through port, and the 3rd port 3 is couplingPort, isolated port open circuit.

Accompanying drawing 4 is port reflectance factor and transmission coefficient curves of each port of the present embodiment. The implication of Sij is: energyInject from j mouth, record energy at i mouth. S₁₁Be expressed as energy and the first port one input energy ratio from the first port one reflectionSquare root; S₂₁When being expressed as the second port 2 and mating, the first port one is to the forward transmission coefficient of the second port 2; S₃₁Be expressed asWhen the 3rd port 3 mates, the forward transmission coefficient of the first port one to the three ports 3. In Fig. 4, can find out, from 2.3GHz toIn the frequency range of 3.2GHz, S₂₁And S₃₁All be less than 3.5dB, S11 is greater than 10dB.

Fig. 5 is that in the present embodiment, (the second port between the output port of coupler circuit emulation is spent in lumped parameter broadband 180With the 3rd port) the amplitude imbalance line of writing music, amplitude imbalance degree is all less than 0.3dB at 2.2GHz in 3.2GHz.

Fig. 6 is that in the present embodiment, (the second port between the output port of coupler circuit emulation is spent in lumped parameter broadband 180With the 3rd port) phase unbalance degree curve, phase unbalance degree is all less than 5 degree at 2.2GHz in 3.2GHz.

In sum, coupler is spent in lumped parameter of the present invention broadband 180, compared with traditional 180 degree couplers, hasFollowing good effect:

1) compared to 180 degree couplers of the micro-band forms of tradition, coupler area is spent in lumped parameter of the present invention broadband 180Little, difficulty of processing is little, cost is low;

2) once 180 degree couplers of traditional micro-band forms complete and just can not revise, and by contrast, the present inventionLumped parameter broadband 180 spend coupler use lamped element, there is adjustable property;

3) compared to 180 degree couplers of traditional lumped parameter, coupler is spent the in lumped parameter of the present invention broadband 180Three tie point places have adopted the inductive coupled technology of secondary, have significantly improved bandwidth of operation.

Claims (6)

1. a coupler is spent in the broadband 180 of lumped parameter, comprises four electric capacity and three inductance, and four electric capacity are respectively firstElectric capacity, the second electric capacity, the 3rd electric capacity and the 4th electric capacity, three inductance are respectively the first inductance, the second inductance and the 3rd inductance, itsBe characterised in that, one end of one end of described the first inductance and the first electric capacity is all connected in the first tie point; Described the first inductanceOne end of the other end and the second electric capacity is all connected in the second tie point; The other end of described the second electric capacity, one end of the second inductanceAll be connected in the 3rd tie point with one end of one end of the 3rd electric capacity; One end of the other end of described the 3rd electric capacity and the 3rd inductanceBe connected in the 4th tie point; One end of the other end of described the 3rd inductance and the 4th electric capacity is connected in the 5th tie point; DescribedThe other end of the other end of one electric capacity, the other end of the second inductance and the 4th electric capacity is connected in the 6th tie point; Described first connectsContact connects the first port; Described the second tie point connects the second port; Described the 3rd tie point is connected with earth terminal; DescribedFour tie points connect the 3rd port; Between described the 3rd tie point and earth terminal, be also connected with the 4th inductance; Described the 4th inductanceInductance value be the 1/n of the inductance value of the first inductance, wherein, n is proportionality constant, described proportionality constant between 0.1 to 0.2 itBetween.

2. coupler is spent in the broadband 180 of lumped parameter according to claim 1, it is characterized in that, described the first electric capacity,Two electric capacity, the 3rd electric capacity and the 4th electric capacity have identical capacitance.

3. coupler is spent in the broadband 180 of lumped parameter according to claim 1, it is characterized in that, described the first inductance andThe 3rd inductance has identical inductance value.

4. coupler is spent in the broadband 180 of lumped parameter according to claim 1, it is characterized in that, described the second inductanceInductance value is the half of the inductance value of the first inductance.

5. coupler is spent in the broadband 180 of lumped parameter according to claim 1, it is characterized in that, described the first electric capacity,The capacitance of two electric capacity, the 3rd electric capacity and the 4th electric capacity isWherein, Z_inFor input port impedance, Z_outForOutput port impedance, ω is operating frequency.

6. coupler is spent in the broadband 180 of lumped parameter according to claim 1, it is characterized in that, described the first inductance andThe inductance value of the 3rd inductance isWherein, Z_inFor input port impedance, Z_outFor output port impedance, ω is workWorking frequency.