JPH1056398A - Device and method for temperature correction of portable radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the transmission efficiency and reliability by simplifying a circuit and device constitution. SOLUTION: This device is equipped with mixers 4 and 8 which convert a carrier frequency from an antenna 1 into an intermediate-frequency signal, an IF detector 11 which detects the intermediate-frequency signal converted by the mixer, a CPU 12 which detects received input electric field intensity, and a memory 13 which previously stores a variation value to which the value detected by the CPU 12 varies with temperature, and the difference value can be found from the variation value stored in the memory and the detected value obtained by the CPU 12. Further, a power switch 14 turns ON or OFF the intermediate-frequency signal to limit the input to the IF detector 11, and the input electric field intensity is judged from the difference value between the receive input electric field level detected value and a previously stored reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature correcting device and a temperature correcting method for a portable wireless device, and more particularly to a temperature correcting device and a temperature correcting method for a portable wireless device for obtaining stable receiver performance.

[0002]

2. Description of the Related Art In general, a portable radio has an RSSI (Received Sig) for converting a reception electric field level into a DC voltage value as a reception electric field strength index in a mobile radio.
nalStrength Indicator), and the RSSI voltage is used to determine whether the area is in or out of the service area and to determine the AGC (Automatic GainC).
control signal is used. This RSS
The I voltage requires a temperature correction circuit because the RSSI output in the IF stage of the receiving system has a particular temperature characteristic. Until now, the temperature compensation measures have included the forward voltage of the diode-
Temperature correction was performed using the temperature fluctuation characteristics in the forward current characteristics.

FIG. 4 is a circuit diagram showing a conventional temperature correcting device for a portable radio. In FIG. 4, a reception input signal input from antenna 101 is a band-pass filter (B
Unnecessary components are removed by PF), amplified by the RF amplifier 103, converted into an intermediate frequency signal by one or more mixer circuits 104, and detected by an intermediate frequency (IF) detector 111. In addition, IF detector 111
Outputs an RSSI voltage as a reception electric field index. The RSSI voltage is obtained by converting the electric field intensity received from the antenna 101 into a DC voltage value, correcting the temperature by the temperature detection circuit 116, and reading the corrected temperature via the CPU 112. The power supply circuit 115 is the mixer circuit 1
04 is operated.

FIG. 5 is another circuit diagram showing a conventional temperature correcting device for a portable radio. In FIG. 5, the temperature detector 2
11 is converted from an analog value to a digital value by an analog-to-digital converter 210, and a DC voltage output from the detector 203 is attenuated by referring to a list of control amounts for a predetermined temperature change according to temperature. 207
In the differential amplifier 204, the difference from the standard voltage generation circuit 205 is amplified, and the amount of attenuation of the attenuator 206 of the attenuator 206 is changed so that the output voltage at the output terminal B can be made constant. it can.

[0005]

However, since the conventional temperature compensating device for portable radio equipment uses a temperature detecting circuit, it is necessary to control the quality of parts and the like, and a solid-state deviation of the temperature detecting characteristic can be reduced. This may lead to individual deviations of the radio equipment, and it is necessary to pay attention to the quality of components for keeping the detected value constant between individual members.

Further, in the conventional temperature compensating device, the amount of attenuation of the attenuator in the carrier frequency stage is changed using the detected value of the temperature detector and the correction amount corresponding to the outside air temperature stored in advance. By correcting the deviation,
Since temperature compensation is performed near the threshold level for determining whether or not the received input electric field of the portable wireless device can communicate, there is a possibility that communication may be disabled, and the apparent communication area is reduced.

An object of the present invention is to provide a temperature correction device and a temperature correction method for a portable wireless device which can simplify the circuit and the device configuration.

Another object of the present invention is to improve transmission efficiency and reliability.

Another object of the present invention is to reduce the size and weight.

[0010]

As a means for solving the above-mentioned problems, a temperature correction apparatus and a temperature correction method for a portable wireless device according to the present invention are provided by a conversion means for converting a carrier frequency signal from an antenna into an intermediate frequency signal. A detecting means for detecting the intermediate frequency signal converted by the converting means; an electric field level detecting means for detecting a received input electric field intensity; and a value detected by the electric field level detecting means fluctuating with temperature, and the fluctuating value is determined in advance. A storage unit for storing the data; and a calculation unit for calculating a difference value between the fluctuation value stored in the storage unit and the detection value detected by the electric field level detection unit.

Further, according to the present invention, in the temperature correction means, a power switch for turning on or off the intermediate frequency signal to limit the input to the IF detector, a power switch for controlling the power switch, and a reception input electric field level detection value And a microprocessor for determining the input electric field strength based on a difference value from a reference value stored in advance, and storage means for storing the reference value.

Thus, in the present invention, utilizing the fact that the detected value of the electric field level has a deviation due to the temperature, the received input signal is stored by using a difference value between the reference value and the detected value which are stored in advance and uniquely determined. By correcting the electric field level, it is possible to eliminate the temperature input of the received input electric field level detection value, further reduce the number of components such as temperature detectors, suitable for miniaturization or weight reduction and further high integration. Things.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A temperature correcting device and a temperature correcting method for a portable wireless device according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a temperature correction device for a portable wireless device according to an embodiment of the present invention. FIG. 2 is a circuit diagram illustrating a main configuration of the temperature correction device for the portable wireless device in FIG.

In FIGS. 1 and 2, a reception input signal from antenna 1 is a bandpass filter (BP).
F) 2 and the bandpass filter 2 removes unnecessary components from the received input signal. The signal output from the bandpass filter 2 is a high-frequency amplifier (hereinafter referred to as “R
F amplifier 3). The amplified output from the RF amplifier 3 is input to a two-stage double superheterodyne circuit.

In this circuit, a received input signal received from an antenna 1 is input to an RF amplifier 3 via a bandpass filter 2 and amplified by the RF amplifier 3, and the amplified output is sent to a first-stage mixer 4. input. Also the first
The output of the mixer 4 at the stage is a band-pass filter 6, R
The signal is input to the second-stage mixer 8 via the F amplifier 7. The output of the second-stage mixer 8 is frequency-converted to an intermediate frequency (IF). The frequency-converted signal is input to an IF detector 11 via a band-pass filter 10, where the signal is subjected to detection and RSSI (Received) as a received electric field index.
(Signal Indicator) voltage.

The output from the IF detector 11 is a detection output 5
The detection output is input to the CPU 12. CPU1
Reference numeral 2 designates an instruction to write a signal corresponding to the frequency signal in the storage area of the memory 13 in advance, and an instruction to read the frequency signal stored in the storage area of the memory 134. Further, the CPU 12 supplies a signal for performing on / off control of the power switch 14 to the power switch 14. The mixers 4 and 8 are operated by opening (off) and closing (on) the power switch 14 according to the on / off control signal of the power switch 14. The power switch 14 is operated by a power supply voltage supplied from a power supply circuit 15.

In this embodiment, after the power of the mobile radio is turned on, a correction voltage due to the ambient temperature fluctuation of the power switch 14 is stored in the correction circuit 20 in order to obtain a correction value due to the ambient temperature at the intermediate frequency stage. Here, first, a switching instruction for switching the switch, which previously turned off the power switch 14 to the on operation, is performed. Power switch 14
, The standby operation (delay operation), the communication operation, and the reading of the RSSI voltage are started. The RSSI voltage can be read by correcting the output detection voltage of the intermediate frequency stage by using the output detection correction voltage of the intermediate frequency stage in the correction circuit 20 to obtain the RSSI voltage.

FIG. 3 shows the characteristics of the IF detector 11,
FIG. 4 is a diagram illustrating that an SI voltage has a temperature-dependent deviation. In FIG. 3, at the same input electric field level, R
3 shows a temperature characteristic with respect to the SSI voltage. When the power switch 14 of FIGS. 1 and 2 is off, that is, the normal temperature is a solid line, and the dotted line is a low temperature. The voltages on the vertical axis of FIG. 3 indicate the respective R values at normal temperature and low temperature when the power switch 14 is off and at low temperature when the power switch 14 is on.
Plot the SSI voltage. The horizontal axis plots the received electric field strength to obtain the characteristics at low temperature and normal temperature as shown in FIG.

In order to obtain such a characteristic as shown in FIG. 3, a process as shown in FIG. 4 is required.

FIG. 4 is a flow chart for explaining the operation of the temperature correcting device for a portable radio device according to the embodiment of the present invention. In the flowchart shown in FIG. 4, step 400 is described as S400.

After the main power of the portable radio is turned on, the power switch 14 is turned off under the control of the CPU 12 in order to obtain a correction value based on the ambient temperature. At this time,
By limiting the reception signal to the detector 11, the characteristics shown in FIG. 3 can be obtained.

First, in the flowchart of FIG.
Power on 400. Next, in S402, the switch 14 is turned off. Next, the process proceeds to S404, where V _OFF 0 is read from the memory 13, and a difference from V _OFF 1 is calculated. That is, it is calculated from ΔV = V _OFF 0−V _OFF 1.
Next, the process proceeds to S406, where ΔV is stored in the memory 13.

Next, the flow proceeds to S408, where the power switch 14 previously turned off is turned on under the control of the CPU 12, and then the flow proceeds to S410 to start the receiving operation. In step S412, the RSSI voltage is monitored. That is, it is calculated by V _ON = V _ON 1 + ΔV. This is because when switching the channel in the reduction of the reception electric field level which is each operation according to the reception electric field level, or performing display outside or inside the service area, the CPU 12 performs the calculation represented by the following equation. As a result, the corrected V _ON can be obtained.

Next, the process proceeds to S414, in which a channel switching at the time of electric field level deterioration, which is a task, and activation for out-of-service display are performed. When the task starts (Y in S414)
In the case of ES, the process proceeds to S416, where task processing is performed. When the task has not been activated, the process returns to S412.

In FIG. 1, the supply of power by the power switch 14 extends to all of the mixer 4, the oscillator 5, the mixer 8 and the oscillator 9, but one or more of the power supplies are cut off or By shutting off the reception signal to the IF detector 11 by the power switch 14, the same result as described above can be obtained.

In the present embodiment, utilizing the fact that the detected electric field level has a deviation due to temperature, it is stored in advance in the memory 13 and received using a difference value between a uniquely determined reference value and the detected value. By correcting the input electric field level in the temperature correction circuit 12, the influence of the temperature of the received input electric field level detection value can be eliminated, the number of components such as the temperature detector can be reduced, and the size or weight can be reduced. It can be suitable for high integration.

[0027]

As described above, according to the temperature correction device and the temperature correction method for a portable wireless device of the present invention, the outside air temperature can be detected by the electric field level detection means without using a temperature detector. Eliminating the temperature deviation of the received input electric field level by correcting the received input electric field level using a correction value that is stored in a memory or the like in advance and uniquely determined by the temperature by using the fact that the electric field has the deviation. Thereby, a communication area without deviation can be secured.

Further, according to the present invention, the outside temperature can be corrected for the temperature deviation by the microprocessor which determines the received input electric field strength based on the correction value stored in advance, and the variation of the correction circuit can be eliminated. And the like.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a temperature correction device and a temperature correction method for a portable wireless device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a main configuration of a temperature correction device of the portable wireless device in FIG. 1;

FIG. 3 is a diagram illustrating general characteristics of an RSSI voltage using the temperature correction device of FIG. 1;

FIG. 4 is a flowchart illustrating an operation of the temperature correction device of the portable wireless device in FIG. 1;

FIG. 5 is a block diagram illustrating a configuration example of a conventional temperature correction device.

FIG. 6 is another block diagram illustrating a configuration example of a conventional temperature correction device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Band pass filter 3 High frequency amplifier 4 Mixer 5 Oscillator 6 Band pass filter 7 High frequency amplifier 8 Mixer 9 Oscillator 10 Band pass filter 11 IF detector 12 CPU 13 Memory 14 Power switch 15 Power supply circuit

Claims (4)

[Claims] A converter for converting a carrier frequency signal from an antenna into an intermediate frequency signal; a detector for detecting the intermediate frequency signal converted by the converter; an electric field level detector for detecting a received input electric field intensity Storage means for previously storing the value of the change in temperature detected by the electric field level detection means, and a difference value between the change value stored in the storage means and the detection value detected by the electric field level detection means A temperature compensating device for a portable wireless device, comprising: calculating means for determining 2. A power switch for turning on or off the intermediate frequency signal to limit an input to an IF detector in the temperature correction means, controlling the power switch, and detecting the received input electric field level. The temperature correction device for a portable wireless device according to claim 1, further comprising: a microprocessor that determines the input electric field strength based on a difference value between the value and a reference value stored in a storage unit in advance. 3. A step of converting a carrier frequency signal into an intermediate frequency signal; a step of detecting the converted intermediate frequency signal; a step of detecting a received input electric field strength; Fluctuates due to
A method for correcting the temperature of a portable wireless device, comprising: a step of storing the variation value in advance; and a step of obtaining a difference value between the stored variation value and a detection value detected by the electric field level detection means. 4. The method of claim 1, wherein said intermediate frequency signal is turned on or off.
Limiting the input of a power supply, and controlling the power supply, and determining the input electric field strength based on a difference value between the received input electric field level detection value and a reference value stored in advance. The method according to claim 3, wherein the temperature of the portable wireless device is corrected.