CN88200494U - Uhf duplexer - Google Patents

Abstract

The utility model discloses a three-terminal passive high frequency element which is assembled by two groups of band-reject filters, which belongs to a collecting and emitting common UHF duplexer. An LC return circuit of one end of the circuit adopts a helical resonator of an auto inductive coupling. The LC return circuit of the other end adopts the helical resonator of a transformer coupling. A quarter-wave accurate coaxial line which is used as a phase reversal device is made into a spiral shape. The UHF duplexer composed by all the characteristics reduces the volume. The UHF duplexer can be provided with a portable radio station. The utility model has the advantages of low cost, convenient fabrication, convenient adjustment, and enhanced selectivity.

Description

UHF duplexer

The utility model relates to the passive high-frequency element of a kind of three ends, belongs to the shared UHF duplexer of sending and receiving, and it comprises following several architectural feature, is combined by cavity, coaxial wire and two kinds of band stop filters.

At present, telephone set is the VHF frequency range in the prior art, makes high pass filter and low pass filter with lumped-parameter elements such as electric capacity, inductance, forms high pass low-resistance and low pass high resistant characteristic with the coaxial resonator trap, and weak point is that volume is big.And for example SGQ-3/3A type duplexer adopts coaxial resonator, and weak point also is that volume is big, and its volume is 250 * 150 * 30mm ³, in the light mobile station of can not packing into, use very inconvenient and can not use many radio frequency channels.

The purpose of this utility model is to avoid above-mentioned the deficiencies in the prior art part, provides a kind of volume the little shared UHF duplexer of sending and receiving that can pack in the portable station machine and hold several ten radio frequency channels.

The purpose of this utility model can reach by following measure.Using the parallel branch band stop filter of quarter-wave coupling and series branch's band stop filter of quarter-wave coupling and combine duplexer, is the device of receiver and transmitter common antenna.With the antenna end is symmetrical centre, and sending and receiving both sides filter such as all chooses at element responds, respectively is three helical resonators and the combination of making spiral helicine quarter-wave coaxial line, has realized reducing the volume of duplexer.Can be the helical resonator that the autotransformer coupling is adopted in the LC loop of the parallel branch band stop filter of quarter-wave coupling with one side circuit, accent is on the f2 frequency, length is that the accurate coaxial line of λ 2/4 is 90 ° of paraphase devices, and characteristic impedance is 50 ohm; The another side circuit is series branch's band stop filter of quarter-wave coupling, LC adopts in the loop transformer-coupled helical resonator, be tuned on the f1 frequency, length is that the accurate coaxial line of λ 1/4 is 90 ° of paraphase devices, and characteristic impedance also is 50 ohm.

The circuit passband is f1 ± 1.5MHz on one side, and stopband is f2 ± 1.5MHz; Another side circuit passband is f2 ± 1.5MHz, and stopband is f1 ± 1.5MHz.Be symmetrical centre with the intermediate ends promptly, Yi Bian be high pass low-resistance characteristic, another side is low pass high resistant characteristic.

The drawing of accompanying drawing is described as follows:

Fig. 1 is a UHF duplexer practical circuit diagram.

Fig. 2 is the structural representation of UHF duplexer.

Fig. 3 is UHF duplexer amplitude-frequency characteristic figure.

The utility model will be described in further detail in conjunction with the embodiments.00 '-11 ' section is a left side circuit among Fig. 1, and 00 '-22 ' section is the right circuit.The spiral coiling of helical resonator among the figure two ［ 5,8 ］ is the spiral inner wire, and length is approximately equal to λ 0/4 and λ 0/4+3mm, is the silver-coated copper wire of φ 2.In order to prevent winding deformation and vibration, support with the tetrafluoroethene skeleton.Helical resonator ［ 8 ］ is transformer coupled device, two quatrter-wavelength lines that enter cavity ［ 9 ］ are respectively from closing on cavity, outer conductor is welded on the wall of chamber, heart yearn enters in the cavity and links to each other respectively with coupling loop ［ 10 ］ two ends, ring is a circle, adopt φ 0.3 silver-plated optical copper wire to make, coaxial with it in the helical resonator bottom, obtained factor Q best in quality ₀Value and improved the inhibition degree.Helical resonator ［ 5 ］ is the autotransformer coupling device, the outer conductor that enters two quatrter-wavelength lines in the cavity also is to be welded on the cavity wall, two heart yearns link to each other in the chamber, and are connected with helix tap position by φ 0.3 silver-plated optical copper wire ［ 4 ］, and the tap number of turn is 1/8 circle.More than two kinds of coupling devices can be by changing coupling loop ［ 10 ］ size and the distance between ring and helix.Reach the fine setting bandwidth of rejection to change the tap position; Simultaneously the resonator open end is provided with micrometer adjusting screw ［ 6 ］, and its equivalence is an adjustable condenser, with being screwed into and back-outing of screw, realizes the frequency trim of band stop filter.［ 2 ］ and ［ 12 ］ be quarter-wave SFT-50-3 coaxial line, both differ 3mm at length.Because being segmentation, quarter-wave connects, the connection place is emotional resistance, thus radiating circuit 11 ' locate to insert one section transmission line SFT-50-3 coaxial line ［ 3 ］, length can be 25mm less than λ 1/4, be capacitive reactances, the effect of tool compensating impedance.

［ 1 ］ and ［ 13 ］ be the SFF-50-2-1 cable of band L6-50J High-frequency plug, length differs 100mm; ［ 14 ］ for being with the SFF-50-3 cable of L16-50K high-frequency socket; ［ 11 ］ be the copper front shroud.

The passband of present embodiment left side circuit is 454.1～457.1MHz, and stopband is 464.1～467.1MHz; The right circuit passband is 464.1～467.1MHz, and stopband is 454.1～457.1MHz.

The utility model compared with prior art has following advantage owing to adopted above-mentioned two kinds of coupling devices:

1. reliable and stable, helical resonator has corpusculum at VHF and UHF frequency, and the volume of the utility model duplexer is 35 * 180 * 30mm³Be 1/8 of SGQ-3/3A duplexer volume, in the portable station of can packing into, for condition has been created in the miniaturization in radio station;

2. the duplexer volume is little, and materials are also few certainly, reduced cost;

3. productivity is good, and technology is simple, and debugging is convenient, has improved selectivity and stopband attenuation, and fine-tuning bandwidth can reach bandwidth 2MHz in the regulation frequency domain, is suitable for 80 channels.

Claims (4)

1, a kind of duplexer of transmit-receive sharing is made up of cavity [9], resonator [5,8], quarter-wave coaxial line [2,12], coaxial wire [1,13,14], cover plate [7], it is characterized in that adopting the combination of two kinds of band stop filters.

2, by the described duplexer of claim 1, it is characterized in that using the very narrow microwave filter of stopband, sending and receiving two circuit such as all choose at the element type response, respectively are three helical resonators and the combination of making spiral helicine quarter-wave coaxial line.

3,, it is characterized in that transformer-coupled helical resonator is adopted in the LC loop in the circuit of one side by the described duplexer of claim 2.

4, by the described duplexer of claim 3, it is characterized in that coupling loop is coaxial with it in the bottom of helical resonator in the transformer coupled device.

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