JPH05251943A - Transmission power controller - Google Patents

Abstract

PURPOSE:To suppress interference between channels by suppressing production of a distortion component caused by the transient state of a leading and a trailing of a multi-carrier output signal at application and interruption of power. CONSTITUTION:A frequency of a local oscillation signal generator 2 fed to a frequency converter is detected by a frequency detector 3, a time constant circuit 7 having a time constant T1 controls a variable attenuator 4 to suppress an output signal from a transient state of a local oscillator 2 and an amplifier 5 at the input of a power supply control signal till the steady-state. In such a transmission power control system, a second time constant circuit 8 operated immediately at the interruption of the power supply control signal is provided, a variable attenuator 6 is controlled to the position of attenuation when the power supply control signal is for a time constant T2 to suppress the interference of the output signal onto an adjacent radio channel depending on the transient state caused at the interruption of the power supply control signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission power control device, and more particularly to a transmission power control device for suppressing interference with other channels in a radio transmission device transmitting a microwave multi-carrier signal.

[0002]

2. Description of the Related Art In a conventional transmission power control device, as shown in FIG. 2, a steady-state input signal is input to a frequency converter 1,
It is mixed with the local oscillation signal of the local oscillator 2 and input to the variable attenuator 4. After passing through the variable attenuator 4, it is amplified by the amplifier 5 and becomes an output signal. Here, in the operation of the conventional power control system, when the power supply control signal 9A is input from the outside, the power supply circuit (PS) 9 starts current supply in the order of the circuit local oscillator 2 and the amplifier 5. Local oscillator signal frequency detector 3
Detects that the current-supplied local oscillator 2 has reached a normal frequency, outputs a control signal 3A to PS9,
The current supply to the amplifier 5 is started. On the other hand, the control signal 3A is also input to the time constant circuit 7, controls the variable attenuator 4 after a lapse of T1 time, and supplies the output of the frequency converter 1 to the amplifier 5. As a result, the output signal of the amplifier 5 is output after the local oscillation signal and the amplifier 5 are not in a transient state when the power supply control signal 9A is input, but in a steady state, and a distortion component does not occur and they are adjacent to each other. It didn't affect the wireless channel.

[0003]

In this conventional transmission power control device, the power is controlled only when the power control signal is input, but is not controlled at the time when the power control signal is cut off. Therefore, the power is cut off. At the same time, since the current supplied to each circuit is cut off at the same time, each circuit enters the transient state in an unfixed order, and the output signal becomes unstable. As a result, there is a drawback in that an output signal containing distortion is generated from the power failure until the supplied current is completely cut off, and interferes with an adjacent wireless channel.

[0004]

A transmission power control apparatus according to the present invention comprises a local oscillator for generating a local oscillator signal, a frequency converter for mixing the local oscillator signal and an input signal, and a steady frequency of the local oscillator signal. Detecting a frequency, a first time constant circuit that delays a control signal of the frequency detector by a time constant T1, and a first time constant circuit that changes an attenuation amount of the signal by an output signal of the first time constant circuit. Variable attenuator, an amplifier that amplifies the output signal of the first variable attenuator, a second time constant circuit that outputs a control signal for a time T2 immediately when a power supply control signal disconnection is input, and the time T2 only. A second variable attenuator that receives the output control signal and attenuates the output signal of the amplifier.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. Figure 1
2, the same reference numerals as those in the conventional example in FIG. 2 have the same functions. That is, in this embodiment, the time constant attenuation controller 8 and the variable attenuator 6 which are the second time constant circuit are added.

Next, the operation of this embodiment will be described. When the power supply control signal 9A is input, the local oscillator 2 goes through a transient state and enters a steady state. When the frequency detector 3 detects that the steady state has been reached, the control signal 3A controls the PS 9 to supply current to the amplifier 5. Assuming that the time during which the amplifier 5 goes into a steady state through a transient state is T1, the time constant circuit 7 controls the variable attenuator 4 after T1 has elapsed to reduce the amount of attenuation and output an output signal. On the other hand, the variable attenuator 6 has zero attenuation in the steady state. When the power supply control signal 9A is cut off, the time constant attenuation controller 8 immediately controls the variable attenuator 6 to put a predetermined amount of attenuation during the time T2. This T2
The time of is adjusted to the time when the current supply to each circuit becomes zero. Therefore, when the power supply control signal 9A is cut off, the variable attenuator 6 is immediately controlled to increase the amount of attenuation to attenuate the output signal and the amplifier 5 until the supply current becomes zero.
It is possible to attenuate and suppress an output signal including distortion that occurs during the transient state of.

[0007]

As described above, according to the present invention, by providing the time constant circuit corresponding to the input of the power supply control signal, the time constant circuit corresponding to the disconnection of the power supply control signal, and the variable attenuator of the transmission output section, This has the effect of suppressing an output signal containing distortion caused by a transient state inside the transmitter.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional transmission power control device.

[Explanation of symbols]

 1 frequency converter 2 local oscillator 3 frequency detector 4, 6 variable attenuator 5 amplifier 7 time constant circuit 8 time constant attenuation controller 9 power circuit

Claims (1)

[Claims] 1. A local oscillator that generates a local oscillator signal, a frequency converter that mixes the local oscillator signal and an input signal, a frequency detector that detects a stationary frequency of the local oscillator signal, and a frequency detector of the frequency detector. A first time constant circuit that delays the control signal by a time constant T1, a first variable attenuator that changes the amount of signal attenuation according to the output signal of the first time constant circuit, and the first variable attenuator. , An amplifier for amplifying the output signal of the amplifier, a second time constant circuit for immediately outputting the control signal for the time T2 when the power supply control signal is disconnected, and an output signal of the amplifier for receiving the control signal for the time T2. And a second variable attenuator for attenuating the transmission power control device.