JPS5847336A - Infinite phase shifter - Google Patents

Abstract

PURPOSE:To simplify the constitution and to obtain the excellent wide band characteristics, by constituting various types of hybrids with the constant impedance and controlling independently only the signal level by means of a variable attenuator of constant impedance. CONSTITUTION:Various types of hybrids 1, 2, 4 and 5 are constitued with the constant impedance, and the signal phase of each arm is previously fixed. Then only the signal level is controlled independently by means of a variable attenuator 3. In such a way, the constitution is simplified with excellent wide band characteristics for an infinite phase shifter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infinite phase shifter used in space diversity systems such as microwave communication systems.

Conventionally, infinite phase shifters used in space diversity systems have been proposed, such as those applying a balanced modulator and those that perform frequency conversion using a local oscillator and control the phase of the local oscillator. However, the former method, which uses a typical ring modulator, has problems with wideband characteristics and high frequency characteristics, and the latter method has a complicated configuration and has problems in removing unnecessary interference waves.

SUMMARY OF THE INVENTION An object of the present invention is to provide an infinite phase shifter that overcomes the above-mentioned deviation and has a simple configuration and excellent broadband characteristics.

To achieve the above object, the infinite phase shifter according to the present invention comprises:
means for branching an input signal to be phase-shifted into two with a phase relationship of in-phase or mutual vcoA;
means for inverting the phase of the input signal, and means for controlling the signal level independently of the preceding phase inverting means, and the phase inverting means or the signal level control means is determined in accordance with the value to be phase-shifted of the input signal. 1yR1ill! means for controlling one of the two branched signals to a predetermined level signal having a phase relationship of 0'' or 180'' with respect to the signal/signal; a second modulating means having the same configuration as the first modulating means and converting the second signal into two branches to a predetermined level signal with a phase relationship of 0'' to 18♂; and a second modulating means storing the control signal. the first memory element; It consists of a means for synthesizing the signals of the second modulating means so as to have the same phase or a good phase relationship.

According to the above configuration, the object of the present invention can be completely achieved.

The present invention will be explained in more detail below with reference to the drawings. Fig. 1 is a configuration diagram showing a first embodiment of the present invention. In the figure, identical components IIc of the first modulation means and the second modulation means are given the same reference numerals. Input trend 101
The input signals M1 of are mutually i
Two out-of-phase signals, M and M, [are divided into two.

Ma1. 18♂) Two signals MA, -MA4 and MA, , -MA, which are in opposite phases to each other, are generated by hybrid 2.

It is branched into. Ma,, - Ma6. Ma1. -ma, are each level controlled by a variable attenuator, 3, respectively, ma,
, -Ma1. The level of the signal is converted to a signal of ma, , -ma,. Ma, and Ma, and Ma, and Ma are each synthesized by the in-phase hybrid 4 vl. , ma, 1 signals are formed.

Ma,. Toma. In-phase synthesis is performed by the #2 in-phase hybrid 5, and an output signal M12 is output from the output terminal 102.

The anti-phase hybrid 2, the two variable attenuators 3 connected thereto, and the in-phase hybrid 4 constitute an O-z amplitude modulator which is the first and second modulation means. −1: The signal amplitude modulated by the amplitude modulator is
An infinite phase shifter is constructed by orthogonally combining the S hybrid 1 and the in-phase hybrid 5.

FIG. 3 is a vector diagram for explaining the phase shifting operation.

This will be explained below using this vector diagram.

Signal vector maπ (sperm
4) moves on a No. 16 vector (Mura, = No. 4-) which moves on n and passes through another 0-π modulator. If the amplitude of the output signal piece is p, then p! = t f, 11 +1 viscosity 1!
・・・・・・・・・■ Also, if the phase angle with reference to n of the bow is θ, then ma1゜” pc tiger θ・・・・・・・・・■
Mao=pminθ...■. The attenuation amount of the four variable attenuators 3 is controlled by control terminals 103, 104, 105, and 106 so that the IJjR width of this bow and the village maintains the relationship of sin and c'o5 of ■ and ■. Signal MA1. is moved on the circumference with radius p to actually determine an ideal Hama-limited phase shifter. However, in a general VC, the variable attenuator 3 is used so that the enclosure of ■ and ■ is always maintained at 1c.
is extremely difficult to control. There, the unexploded E4
Pi solves the above problem by using various types of memory elements IO. In other words, to the extent that there is no practical problem<
The control signal, that is, the control voltage and control current, of the variable attenuator which divides the control phase angle into fC (for example, 360/127-2.8") and gives these discrete phase angles in the memory element 10 is stored in advance, and the phase The control is performed by extracting this stored control signal and applying it to the control terminal.
Ru. Next, the problem of broadband cannot be solved simply by using the memory element 10.

In other words, conventionally, these 0-π modulators are composed of balanced modulators, etc., and they have problems with broadband characteristics, such as using a transformer, and controlling the amount of attenuation changes the impedance, resulting in a large change in transmission characteristics. There is. Therefore, in the present invention, various 11 hybrids such as 1.24 and 5 are configured with constant impedance, and the phase of the signal of each arm is fixed. It's like you want to control it. In this way, an infinite phase shifter with a simple configuration and excellent broadband characteristics can be constructed.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention. In FIG. 1, an 18♂-1 hybrid 2° in-phase hybrid 4 and two variable attenuators 3 are constructed. The O-π modulator, which is the second modulation means, is
It differs from FIG. 1 in that it is composed of a variable attenuator 6 and a variable attenuator 3. Here, it is used only to invert the phase of the balanced modulator 6, and the phase of the signal passing through the control terminal 107 or 108 is inverted to ♂ or 180'. Similar to the first embodiment of Signal Level Co., Ltd., the attenuation amount of the variable attenuator 3 is controlled by the terminal 1.
Controlled by 09 and ll0K. Further, as in the case of the first embodiment, these phase inversion and level control values are stored in advance in the storage element 101. In this embodiment as well, since the impedance of each circuit component is constant, the high frequency broadband characteristics are not impaired.

The second embodiment has been described above, and various modifications can be made within the scope of the present invention.

For example, in FIG. 1, the 9Q/% hybrid I and the in-phase hybrid 5 can be replaced in FIG. 180° - Hybrid 2 and in-phase hybrid 4
It is also possible to replace.

Furthermore, the variable attenuator 3 can be replaced with a variable gain amplifier.

As explained in detail above, according to the present invention, an infinite phase shifter with excellent high frequency broadband characteristics, which was difficult to achieve using only a balanced modulator, can be realized with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a first embodiment of the invention, FIG. 2 is a circuit diagram of a second embodiment of the invention, and FIG. 3 is a vector diagram for explaining the principle of operation. 1... Ihybrid 2... 18♂ hybrid 3... Variable attenuator 4, 5... In-phase hybrid 6... Heijutsu variable p4 device lO... Memory element 1
01...Signal input-102...Signal output terminal 10
3,104゜105.106.109.110... Variable attenuator side gIJ Koko 107゜108... Phase control terminal of balanced modulator Special fraud applicant NEC Corporation agent Patent attorney Hisashi Inoro・Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] Means for branching the input signal to be phase-shifted into two with the same phase or mutual K (X5 phase relationship, and at least the phase ♂17t is 18
0, and means for controlling the signal level independently of the phase inverting means, the phase inverting means or the signal level control means being determined in accordance with the value to be phase shifted of the input signal. a first modulating means that converts one of the two branched signals into a signal of a predetermined level with a phase relationship of ♂ or 186 for each signal of the first modulating means; The above 2 in the configuration
Spread the other branched signal by 0°t with respect to this signal.
a second modulating means for converting signals of a predetermined level with a phase relationship of 80 degrees, a storage element storing the control signal, and a signal of the first and second modulating means to be in phase or in phase; An infinite phase shifter characterized by comprising means for synthesizing with a relation.