CN201450518U - Broadband 6-port direct QPSK modulator - Google Patents

Abstract

The utility model relates to a broadband 6-port direct QPSK modulator, which comprises a 6-port module [1], wherein the 6-port module [1] comprises three quadrature couplers [10] and a wilkinson power distributor [11]. The broadband 6-port direct QPSK modulator is characterized in that a port 1 of the 6-port module [1] is a radio frequency input end RF, a port 6 of the 6-port module [1] is a modulated radio frequency output end MRF, a port 2, a port 3, a port 4 and a port 5 of the 6-port module [1] are respectively connected with dynamic contacts of a first switch [20], a second switch [30], a third switch [40] and a forth switch [50], stationary contacts of the first switch [20] and the second switch [30] are connected, a connecting point thereof is an ID ATA input end, the third switch [40] and the forth switch [50] are connected, and a connecting thereof is a QD ATA input end. The broadband 6-port direct QPSK modulator uses the 6-port module of a commercial element, thereby achieving direct QPSK modulation from 1GHz to 2GHz.

Description

The direct qpsk modulator of broadband 6 ports

Technical field

The utility model relates to the microwave communication field, the direct qpsk modulator of especially a kind of broadband 6 ports.

Background technology

Quadrature Phase Shift Keying (QPSK) is meant the phase shift keying scheme of two bits of primary modulation, selects a kind of (0,90,180 or 270 degree) of four kinds of carrier phase.Under the same band condition, QPSK can carry the amount of information of traditional PS K modulation twice.QPSK is used for satellite communication, cable modem, video conferencing system, cell phone and other digital communication of transmitting MPEG 2 video signal.

Digital wireless communication critical component wherein is a modulator.Because the relation of cost, directly modulation (direct-conversion) becomes popular digital modulation mode in recent years.Conventional digital modulation adopts frequency mixer as frequency converter, to realize direct QPSK modulation.Many problems are all relevant with this structure.For instance, VCO draws (VCO pulling), exactly because radio-frequency (RF) output end leaks into the caused problem that is very difficult to solve of local oscillator.

Summary of the invention

The purpose of this utility model is to overcome above-mentioned defective, provides broadband 6 ports direct qpsk modulator.The technical solution of the utility model is:

The direct qpsk modulator of a kind of broadband 6 ports, comprise 6 port modules, 6 port modules comprise three orthocouplers and a Wilkinson power divider, the port Port1 of described 6 port modules is rf inputs RF, the port Port6 of 6 port modules is modulated RF output MRF, the port Port2 of 6 port modules, port Port3, port Port4 and port Port5 are connected the moving contact of first switch, second switch, the 3rd switch and the 4th switch respectively, the fixed contact of first switch and second switch interconnects, and its tie point is the IDATA input; The fixed contact of the 3rd switch and the 4th switch interconnects, and its tie point is the QDATA input.

The port Port 1 of described 6 port modules, port Port2, port Port3, port Port4, port Port5 or port Port 6 connect resistance and electric capacity.

The beneficial effects of the utility model are:

The utility model adopts 6 port modules of commercial component, thereby realizes directly in the QPSK modulation of 1Ghz to 2Ghz.The utility model circuit structure is simple, and is with low cost, and excellent performance has very big practical value.Respond well in engineering is used, to use flexibly, debugging is convenient.

Description of drawings

Fig. 1 is 6 port module schematic diagrams.

Fig. 2 is a structured flowchart of the present utility model.

Fig. 3 is a test framework block diagram of the present utility model.

Embodiment

Below in conjunction with accompanying drawing the utility model is further described:

Design principle of the present utility model is:

As Fig. 1,6 port modules 1 comprise three quadrature coupling apparatus 10 and a Wilkinson power divider 11.The S parameter of 6 port modules 1 is:

$\left[s\right]=\left(\begin{array}{cccccc}0& j/2& -1/2& -1/2& j/2& 0\\ j/2& 0& 0& 0& 0& -1/2\\ -1/2& 0& 0& 0& 0& j/2\\ -1/2& 0& 0& 0& 0& 1/2\\ j/2& 1/2& 0& 0& 0& j/2\\ 0& -1/2& j/2& 1/2& j/2& 0\end{array}\right)$

Defined variable Γ ₂₃, and make it to equal the reflection coefficient Γ of port 2 and port 3 ₂And Γ ₃, Γ ₂₃=Γ ₂=Γ ₃Equally, definition reflection coefficient Γ ₄₅=Γ ₄=Γ ₅, Γ ₄And Γ ₅Be the reflection coefficient of port 4 and port 5, thereby can draw the fundamental formular of following 6 port QPSK modulation:

(S ₆₁) _SP＝-(Γ ₂₃+jΓ ₄₅)/2。

Table 1 has been listed the calculated value of 6 port QPSK modulation constellation tables.

Table 1 six port qpsk modulator constellation tables

As Fig. 2, the utility model comprises one 6 port module 1 and four switches 20,30,40,50.

The design no less important of switch.Also both required switch 20,30,40,50 that good short circuit (G=-1) and open circuit (G=+1) reflection index are arranged.Be reflected on the table 1, too big phase place and amplitude imbalance should not arranged. Switch 20,30,40,50 should have good switching speed, and input and output also should have the good isolation degree between the control end simultaneously.

Quadrature coupling apparatus 10 adopts the Model 11305-3S type quadrature coupling apparatus of U.S. Anaren Inc..

In the application of reality, can use electric capacity and resistance to come better span of control limit of control balance and phase equilibrium.

As Fig. 3, test framework block diagram of the present utility model.As seen from the figure, the QDATA output of the upright ME522A type error code device of peace connects QDATA input of the present utility model, and the IDATA output of the upright ME522A type error code device of peace connects IDATA input of the present utility model.The signal output part of Agilent E4438C type ESG series vector signal generator connects rf inputs RF, and modulated RF output MRF connects frequency mixer 2, sieve sieve ﹠amp; The R﹠amp of Shi Mici; The output of S SMIQ type vector signal generator connects frequency mixer 2, obtains the intermediate-freuqncy signal of 36MHz after frequency mixer 2 mixing.The rf modulated signal process frequency mixer 2 of the 1-2Ghz that the direct qpsk modulator of 6 ports produces from the broadband is mixed down the intermediate-freuqncy signal of 36MHz, and this signal is imported into the input of Agilent 89600 type VSAs then.Agilent 89600 type VSAs are used as the QPSK signal that receiver comes 6 ports direct qpsk modulator in demodulation broadband to produce.Agilent 89600 type VSAs are powerful analysis tools, it is equipped with 89600 type VSA software and main frames, main frame is connected with Agilent 89600 type VSAs by the IEEE1394 fire-wire interfaces, provide radio spectrum to show the analysis of fundamental frequency (I/Q), EVM and eye pattern, signal capture, to various analog-and digital-demodulation, and one overlap the time widely, frequency and Modulation analysis instrument.Owing to possess these functions, make Agilent 89600 type VSAs become the standard device of test and appraisal digital communication signal.

The utility model is respond well in engineering is used, and uses flexibly, and debugging is convenient.

The direct qpsk modulator of a kind of broadband 6 ports, comprise 6 port modules 1,6 port modules 1 comprise three orthocouplers 10 and a Wilkinson power divider 11, the port Port1 of 6 port modules 1 is rf inputs RF, the port Port6 of 6 port modules 1 is modulated RF output MRF, the port Port2 of 6 port modules 1, port Port3, port Port4 is connected first switch 20 respectively with port Port5, second switch 30, the moving contact of the 3rd switch 40 and the 4th switch 50, the fixed contact of first switch 20 and second switch 30 interconnects, and its tie point is the IDATA input; The fixed contact of the 3rd switch 40 and the 4th switch 50 interconnects, and its tie point is the QDATA input.

The port Port 1 of 6 port modules 1, port Port2, port Port3, port Port4, port Port5 or port Port 6 connect resistance and electric capacity, come better span of control limit of control balance and phase equilibrium.

In the utility model, connect expression and be electrically connected, in circuit structure of the present utility model, except predetermined annexation, other element that can be electrically connected can also be set betwixt, as switching device, transistor, diode, capacity cell, resistive element etc.

The hardware and software that the utility model does not relate to all can pass through existing techniques in realizing.

Claims (2)

1. direct qpsk modulator of broadband 6 ports, comprise 6 port modules [1], 6 port modules [1] comprise three orthocouplers [10] and a Wilkinson power divider [11], the port Port1 that it is characterized in that described 6 port modules [1] is rf inputs RF, the port Port6 of 6 port modules [1] is modulated RF output MRF, the port Port2 of 6 port modules [1], port Port3, port Port4 is connected first switch [20] respectively with port Port5, second switch [30], the moving contact of the 3rd switch [40] and the 4th switch [50], the fixed contact of first switch [20] and second switch [30] interconnects, and its tie point is the IDATA input; The fixed contact of the 3rd switch [40] and the 4th switch [50] interconnects, and its tie point is the QDATA input.

2. the direct qpsk modulator of broadband 6 ports according to claim 1 is characterized in that port Port1, port Port2, port Port3, port Port4, port Port5 or the port Port6 of described 6 port modules [1] connects resistance and electric capacity.

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