JPS62279707A - Amplitude equipment - Google Patents

Abstract

PURPOSE:To obtain an amplitude characteristic showing a nearly flat straight line in using an amplitude deviation of the longitudinal axis as a logarithmic scale by giving a linear function gradient to the amplitude characteristic to one frequency of an input signal to a synthesis circuit. CONSTITUTION:A hybrid circuit 1 branches an input signal to output signals 1a-1c. Coils L1, L2 and capacitors C1, C2 in a filter 7 are selected to show the amplitude characteristic of linear function increasing to the right. The signal 1a is combined (4) with the signal 1b via the filter 7 and a delay circuit 2 and the combined output is combined (5) with the signal 1c delayed (3) via a variable attenuator 6. As a result, the amplitude characteristic of the equalizer is close to a flat straight line in comparison with the amplitude characteristic of a transversal amplitude equalizer.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a transversal width equalizer used in communication devices and the like.

(Prior art) Conventionally, this type of transversal oscillator @equalizer
As shown in the block diagram of “1”, 3
It is composed of a branch hybrid circuit 1, a first delay circuit 2, a second delay circuit 3 having a delay time twice that of the first delay circuit, combining circuits 4 and 5, and a variable attenuation circuit 6.

Now, the amplitude of the input signal is Ei, and the amplitude of the output signal is Eo.
Then, the ratio Eo/Ei is expressed as follows.

Eo/Ei = L + r Co SWT ・
"" (tlHere, r is the ratio of the two signals synthesized by the synthesis circuit 5 located on the output side, W is the angular frequency, and T
is the delay time of the first delay circuit 2. As can be seen from equation (1), this transversal type amplitude equalizer can continuously vary the amount of amplitude equalization by changing the signal 9r using the variable attenuation circuit 6. At this time, the amplitude deviation with respect to frequency is expressed as shown in Fig. 7 on a logarithmic scale with the amplitude deviation on the vertical axis. 6
Indicates the characteristic of succumbing.

(Problem to be solved by the invention) However, as a general amplitude characteristic required of an amplitude equalizer, when the frequency is expressed on the horizontal axis (and the amplitude deviation on the vertical axis is expressed on a logarithmic scale), the center Characteristics that form a nearly flat straight line across the entire wavenumber region including the frequency fo are desired, and the conventional amplitude characteristics shown in Figure 7 cannot satisfy this, and there is still room for improvement. It was left behind.

The present invention has been made in view of the above-mentioned problems, and m1lii! is a straight line that is as flat as possible when the amplitude deviation on the vertical axis is expressed on a logarithmic scale. The present invention aims to provide an amplitude equalizer having the following characteristics.

(Means for Solving the Problems) In order to solve the above-mentioned problems and achieve the above objects, the amplitude equalizer provided by the present invention inputs a high frequency signal and converts the first signal and the second signal into an amplitude equalizer. and a hybrid circuit that branches and outputs a third signal; a first delay circuit that delays the first signal; and a first delay circuit that combines the output of the first delay circuit and the second signal. a combining circuit, a current reduction circuit that attenuates the output of the first combining circuit, a second delay circuit that delays the third signal, and an output of the second delay circuit and an output of the attenuation circuit. An amplitude equalizer comprising a second combining circuit for combining, the amplitude equalizer having a linear slope in the amplitude characteristic with respect to the frequency of one of the two types of signals inputted to the first combining circuit. The present invention is characterized in that it is provided with a characteristic gradient means that gives the following characteristics.

(Example) FIG. 1 is a block diagram showing one embodiment of the present invention.

First, to explain the configuration, 1.1 is a hybrid circuit that inputs a high-frequency signal, and branches the input signal into three types of signals and outputs a first signal 1a, a second signal tb, and a third signal 1c. do. 7 is a filter, 2 is a first delay circuit, and as shown in detail in FIG.
, and capacitor C1 are resistors Ro and R.

A series circuit consisting of (connected in parallel, a coil at the connection point of resistor R0 and resistor R0, and a parallel circuit of capacitor C1). A delay line is connected from the connection point of capacitor C8 and resistor R0, which is the output terminal of the filter. Delay circuit 2 formed by DL
are connected.

Here, the values of the coil L4sLt and the capacitor C1#Ct forming the filter circuit 7 are selected to be appropriate values so as to provide an amplitude characteristic having a linear function slope upward to the right as shown in FIG.

The filter 7 having such characteristics is used in the first synthesis circuit 4
It acts as a characteristic slope means for giving a linear function slope to the amplitude characteristic with respect to the frequency of the signal input to the input signal. The first synthesis circuit 4 synthesizes the output of the delay circuit 2 and the second signal 1b. Reference numeral 6 denotes a variable attenuation type attenuator, which attenuates the output of the combining circuit 4 to an arbitrary attenuation amount. A second delay circuit 3 delays the third signal 1c by a predetermined delay time.

5 is a second synthesis circuit, which synthesizes the output of the delay circuit 3 and the output of the attenuation circuit 60.

FIG. 4 is a percentage comparison diagram showing the amplitude w characteristic of the embodiment shown in FIG. 1 in comparison with the conventional example. The operation of the present invention will be explained with reference to FIG. The amplitude characteristic of the transversal amplitude equalizer shown in FIG. 1 is changed to that shown in FIG. As shown by solid line 9 in the graph,
Both at low and high frequencies, the amplitude characteristics approach a flat straight line compared to the amplitude characteristics of the conventional transversal type loss width equalization word (broken line 8 in Figure 10).

In addition, in the above embodiment, the amplitude characteristic of the filter 7 is described in which the attenuation amount increases at lower frequencies, but conversely, attenuation 1 increases at higher frequencies. In this case, the equalization characteristic can be similarly flattened.

Further, in the embodiment shown in FIG. 1, the filter 7 is arranged in the # stage of the delay circuit 2, but it may be arranged on the opposite side, and provided between the delay circuit 2 and the synthesis circuit 4.

FIG. 5 is a block diagram showing another embodiment of the present invention. The embodiment shown in FIG. 5 is characterized in that a filter 7 serving as a characteristic gradient means is provided on the second signal lb side.

(Effects of the Invention) As described above, according to the present invention, the first signal of the hybrid circuit is delayed by the first delay circuit, and the delayed output and the second signal of the hybrid circuit are transmitted to the first synthesis circuit. In the amplitude equalizer, the attenuated output is synthesized by the attenuation circuit, and the third signal of the hybrid circuit, which is delayed by the second delay circuit, is synthesized by the second synthesis circuit. By providing a characteristic slope means for giving a linear functional slope to the amplitude characteristic with respect to the frequency of one of the signals input to the first synthesis circuit, the amplitude characteristic can be changed to an amplitude deviation on the vertical axis. When expressed on a logarithmic scale, it is possible to improve the straight line to be as flat as possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment according to the present invention, FIG. 2 is a specific circuit diagram of the filter and first delay circuit in FIG. 1, and FIG. FIG. 4 is a characteristic diagram showing the amplitude characteristics of the filter, and FIG. 4 is a characteristic diagram comparing the amplitude characteristic after equalization obtained by the embodiment of the present invention shown in FIG. 1 with that of the conventional example. FIG. 6 is a block diagram showing an example of the configuration of a conventional transversal type amplitude equalization filter; FIG. 7 is a characteristic diagram showing the amplitude characteristics after equalization in FIG. 6. . DESCRIPTION OF SYMBOLS 1... 3-branch hybrid, 2... 1st delay circuit, 3... 2nd delay circuit, 4.5... Synthesis circuit, 6
...Variable attenuation circuit, 7...Filter circuit, DL...
・Delay line. Agent Patent Attorney Nobu Honjo Bento box 1 diagram, ---,, ----------------j Figure 2 Mr. Lee □ fo □ Yamayo 7 Reaction Figure 3 I & fo , g River wave number 4 Figure 6 Buddha □to □Ayou liquid chichi

Claims (1)

[Claims] A high frequency signal is input, a first signal, a second signal and a third signal are input.
a hybrid circuit that branches and outputs a signal, a first delay circuit that delays the first signal, and a first synthesis circuit that synthesizes the output of the first delay circuit and the second signal. , an attenuation circuit that attenuates the output of the first synthesis circuit, a second delay circuit that delays the third signal, and a second delay circuit that synthesizes the output of the second delay circuit and the output of the attenuation circuit. and a combining circuit, further comprising characteristic slope means for giving a linear functional slope to the amplitude characteristic of one of the signals input to the first combining circuit with respect to the frequency. An amplitude equalizer characterized by: