JPH09162620A - Antenna-controlled type receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To receive a radio wave in an excellent way with a maximum electric field strength by matching the length of an antenna with a reception frequency automatically. SOLUTION: When a frequency control key 31 is used to enter a frequency, a frequency corresponding to the entered frequency is received under the control of an MPU 30 and an electric field strength detector 28 detects an electric field strength detection signal denoting the electric field strength of the received frequency by an antenna 21 and provides an output of the signal to the MPU 30. As soon as a up/down key of the frequency control key 31 is operated, the MPU 30 gives a control signal to an antenna elevating/lowering device 22 to extend or contract the length of the antenna 21, resulting that a level of the electric field strength detection signal detected by the electric field strength detector 28 is changed. The best electric field strength (maximum sensitivity) is selected automatically by extending or decreasing the length of the antenna 21 so as to maximize the level of the electric field strength detection signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna control type receiving apparatus which accurately matches an antenna length to a reception frequency and receives the maximum electric field strength (maximum sensitivity).

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing the configuration of a conventional antenna-controlled receiver. In FIG. 3, this example shows an antenna 1 whose length can be varied, and an antenna elevator 2 for varying the length of the antenna 1 based on a control signal.
And a high frequency amplifier 3 for amplifying a high frequency received signal from the antenna 1. Further, a mixer 4 for outputting an intermediate frequency signal obtained by frequency-converting the high frequency signal from the high frequency amplifier 3, and a local oscillation signal having a voltage corresponding to the local oscillation frequency are output to the mixer 4 to generate a voltage controlled oscillator (VC
O) and the like, and a local oscillator 5 and an intermediate frequency amplifier 6 for amplifying the intermediate frequency signal output from the mixer 4. Further, the detector 7 for detecting the intermediate frequency signal output by the intermediate frequency amplifier 6 and the frequency signal output by the high frequency amplifier 3 and the intermediate frequency amplifier 6 outputs the electric field strength detection signal indicating the electric field strength received by the antenna 1. An electric field strength detector 8 and a loop filter 9 for sending a voltage according to a control signal for the local oscillator 5 to change and output the frequency of the local oscillation signal are provided. Further, it has a microprocessor (MPU) 10 for controlling each part, a frequency operation key 11 for performing an operation for variably setting the reception frequency, and a frequency display liquid crystal display (LCD) 12 for displaying the reception frequency on a screen. ing.

Next, the operation of this conventional example will be described. When the up / down key provided on the frequency operation key 11 is operated to input a desired reception frequency, the MPU1
The control signal from 0 is converted into a DC voltage by the loop filter 9 and input to the local oscillator 5. The local oscillator 5 outputs a local oscillation signal having a frequency corresponding to the DC voltage to the mixer 4. The mixer 4 frequency-converts the high frequency signal, outputs the intermediate frequency signal to the detector 7, and outputs the detection signal from here.

In such an operation, the frequency operation key 1
When the MPU 10 takes in the reception frequency data instructed from 1, the λλ length or ¼λ length of this reception frequency is calculated, and the control signal corresponding to this value is sent to the antenna elevator 2. The antenna elevator 2 adjusts the length of the antenna 1 based on the control signal and performs reception at that frequency. As a result, 1/2 λ or 1/4 λ with excellent reception sensitivity
Since the signal is received with the length of the antenna 1, the good reception state can be obtained.

By thus setting the operation to the preset key (not shown) of the frequency operation key 11, the antenna 1 can be set to the reception frequency by the touch operation.

FIG. 4 is a flow chart showing a processing procedure of the operation by the preset key. In FIG. 4, when setting the current reception frequency to a preset key (not shown) of the frequency operation key 11, the preset key is pressed for a predetermined time or longer, and the working RAM (not shown) in the MPU 10 corresponds to the preset key. A control signal for setting the reception frequency and the length of the antenna 1 is stored (steps S10 and S11). After this storage, when the preset key is pressed down for a short time, the MPU 10 which has received this pressing signal stores the reception frequency assigned to this preset key and the data of the control signal for setting the length of the antenna 1 in the working RAM. (Step S12), the control signal is sent to the antenna elevator 2 to automatically set the length of the antenna 1. MP at the same time
By U10, a predetermined DC voltage corresponding to the read reception frequency is input from the loop filter 9 to the local oscillator 5, the local oscillation signal from this is sent to the mixer 4, and the frequency is received ( Step S13).

As described above, in the conventional antenna-controlled receiver, the desired reception frequency and the wavelength of this frequency are calculated, and the data of the control signal of the length of the antenna 1 is stored in association with the preset key. After that, the antenna 1 is set to be automatically received with the best electric field strength only by pressing the reset key.

[0008] As an improvement proposal of such an antenna control type receiving device, there is an "antenna device" disclosed in Japanese Patent Laid-Open No. 53-21230. In the example of this publication, the length of the antenna element is varied and the standing wave ratio (V.SWR) is always set to a small value to obtain a good reception state with the antenna mounted on the vehicle.

[0009]

However, in the former antenna-controlled receiver of the above-mentioned conventional example, the length of the antenna 1 is set to 1 / 2λ or 1 / 4λ calculated from the reception frequency. Therefore, the signal could not be received with the maximum electric field strength. That is, since the mechanical length is set to 1 / 2λ or 1 / 4λ, it is not possible to set the electrical length to 1 / 2λ or 1 / 4λ in consideration of the shortening rate and the mounting metal part. However, there is a drawback that reception is not possible with a better electric field strength.

Further, in the latter publication, an FM control oscillator for transmitting the transmission signal of the receiving antenna is required to obtain the standing wave ratio, and the standing wave ratio is minimized from the traveling wave and the reflected wave. Must be calculated. Therefore, the calculation process for minimizing the standing wave ratio corresponding to the change in the detected voltage of the traveling wave and the reflected wave due to traveling of the vehicle becomes complicated, and the length of the antenna that can be accurately received with a good electric field strength cannot be set. It is possible.

The present invention solves the problems in the prior art as described above, and an excellent antenna in which the antenna length accurately matches the reception frequency and can be satisfactorily received with the maximum electric field strength (reception sensitivity). A controlled receiver is provided.

[0012]

In order to achieve the above object, the present invention is connected to an antenna element having a variable length, an antenna driving means for driving the variable length of the antenna element, and an antenna element. Receiving means for varying the receiving frequency to receive, and receiving electric field strength detecting means for detecting the receiving electric field strength at the antenna element based on the signal from the receiving means,
Storage means for storing the received electric field strength detection data output from the received electric field strength detection means; and, when the receiving frequency is set by the receiving means, the received electric field strength detection data is stored in the storing means, and the electric field is read and read. The control means sends a control signal to the antenna driving means so as to maximize the strength and performs control for setting the length of the antenna element.

As described above, the antenna control type receiving apparatus can be obtained in which the antenna length is accurately adapted to the receiving frequency and the receiving can be performed favorably with the maximum electric field strength (reception sensitivity).

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is such that an antenna element having a variable length, an antenna driving means for driving a variable length of the antenna element, and the antenna element are connected. Receiving means for varying the receiving frequency to receive, receiving electric field strength detecting means for detecting a receiving electric field strength at the antenna element based on a signal from the receiving means, and receiving output from the receiving electric field strength detecting means Storage means for storing the electric field strength detection data, and when the reception frequency is set by the receiving means, the received electric field strength detection data is stored in the storage means, and the electric field strength is maximized while reading, A control means for transmitting a control signal to the antenna driving means to perform control for setting the length of the antenna element. Since the field strength data is stored and controlled so that the length of the antenna element is set by driving by the antenna driving means so that the electric field strength is maximized while reading the field strength data, Has the effect that the reception is performed well at maximum field strength.

Further, the invention according to claim 2 is the control time and the electric field strength detection data for varying the antenna element length for each of a plurality of reception frequencies when the length of the antenna element is adjusted and set by the reception frequency. And a plurality of selection switches corresponding to each of a plurality of reception frequencies. When the selection switch is operated, reception control is performed at the frequency set in the operated selection switch. And the length of the antenna element at the time of maximum expansion or minimum contraction to be set to the maximum electric field strength based on the control time / electric field strength detection data read from the storage means. The time control signal is sent to the antenna drive means to set the antenna element length,
When the one-touch selection switch is operated, reception control is performed at the frequency set in the operated selection switch, and the maximum extension of the antenna element is performed based on the read control time / electric field strength data. Or, the control signal of the time to set the length from the length at the time of the minimum reduction to the maximum electric field strength is sent to the antenna driving means and set to the length, so that the reception frequency at the reception frequency once received is set. This has the effect of setting the antenna element with a single touch.

Further, the invention according to claim 3 is provided with screen display means, and the screen display means displays on the screen that the length of the antenna element is set to the maximum electric field strength. In addition to the effect of the invention described in item 1, it has the effect of displaying on the screen that the antenna element is set to have the maximum electric field strength.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of an embodiment of an antenna control type receiving apparatus of the present invention. In FIG. 1, an antenna 21 having a variable length and an antenna elevator 22 for continuously varying the length of the antenna 21 based on a control signal are included. Further, a high frequency amplifier 2 for amplifying a high frequency received signal from the antenna 21.
3, a mixer 24 which outputs an intermediate frequency signal obtained by frequency-converting the high frequency signal from the high frequency amplifier 23, a local oscillation signal to the mixer 24, and a voltage controlled oscillator (VC
O) and the like are provided for the local oscillator 25. The intermediate frequency amplifier 26 that amplifies the intermediate frequency signal output from the mixer 24, the detector 27 that detects the intermediate frequency signal output from the intermediate frequency amplifier 26, the high frequency amplifier 23 and the intermediate frequency amplifier 26 output. An electric field intensity detector 28 that outputs an electric field intensity detection signal indicating the electric field intensity received by the antenna 21 from the frequency signal is provided.

Further, a loop filter 29 for transmitting a voltage according to a control signal for varying and outputting the frequency of the local oscillation signal to the local oscillator 25, a microprocessor (MPU) 30 for controlling each unit, and a reception unit It has a frequency operation key 31 for performing an operation for variably setting the frequency. Further, a frequency display liquid crystal display (LCD) 32 for displaying the reception frequency on the screen and a level in the electric field strength detection signal are stored, and also control time versus electric field strength detection data for adjusting the length of the antenna 21 in advance is stored. Matching between the memory 33 and the antenna 21
It has a matching state display LCD 34 for displaying the state and an antenna elevating key 35 operated by the user to change the length of the antenna 21 by manual operation.

Next, the operation of the configuration of this embodiment will be described. FIG. 2 is a flowchart showing the processing procedure of the operation of this embodiment. In FIGS. 1 and 2, when a desired reception frequency is input by operating the up / down keys of the frequency operation key 31, a DC voltage is input from the loop filter 29 to the local oscillator 25 by a control signal from the MPU 30. The local oscillator 25 outputs a local oscillation signal corresponding to this DC voltage to the mixer 24. The mixer 24 frequency-converts the high-frequency signal, outputs the intermediate frequency signal to the detector 27, and outputs the detection signal from this (step S20). In this case, the received frequency by operating the up / down key of the frequency operation key 31 is displayed on the frequency display LCD 32. At the same time, the signals from the high frequency amplifier 23 and the intermediate frequency amplifier 26 are input to the electric field strength detector 28, where the electric field strength detection signal corresponding to the electric field strength of the reception frequency at the antenna 21 is the MPU.
Is output to 30.

When the up / down key of the frequency operation key 31 is operated, a control signal is sent from the MPU 30 to the antenna elevator 22 to extend or reduce the length of the antenna 21. As a result, the level of the electric field intensity detection signal detected by the electric field intensity detector 28 also changes. The level of the electric field strength signal is stored in the memory 33 under the control of the MPU 30 (step S21), and the control signal is sent from the MPU 30 to the antenna elevator 22 so that the level of the electric field strength signal is maximized while reading. Antenna 21
Is adjusted by extending or reducing the length (step S22,
S23). When adjusting the length of the antenna 21, the matching state of the antenna 21 with respect to the received frequency is displayed on the matching state display LCD 34. For example, matched maximum electric field strength (maximum sensitivity)
When it can be received by, the screen display such as "Maximum sensitivity" is displayed.

Further, this operation is performed by the frequency operation key 31.
The preset key (not shown) can be set so that the antenna 21 can be received with the maximum electric field strength with respect to the reception frequency with a touch. In this case, when the length of the antenna 21 is adjusted and set by the reception frequency,
The control time vs. electric field strength detection data for the reception frequency is stored in the memory 33. This control time vs. electric field strength detection data is the length of the antenna 21 extended to the maximum, or
The control time of MPU30 which sets to the length of the antenna 21 which becomes the maximum electric field strength from the length which reduced the most is shown. When a preset key (not shown) of the frequency operation key 31 is pressed, the MPU 30 performs control to set the stored reception frequency, reads the control time vs. electric field strength detection data from the memory 33, and reads the antenna 21. The control time data that gives the maximum electric field strength is sent to the antenna elevator 22 from the maximum length or the minimum length, and the length of the antenna 21 is set.

In this way, in the present embodiment, the length of the antenna is automatically and accurately adapted to the reception frequency, and good reception can be achieved with the maximum electric field strength.

In the present embodiment, only reception has been described, but the present invention can be applied to a wireless transceiver as it is.
That is, the reception frequency at which the maximum electric field strength is obtained by the antenna 21 can be transmitted with the lowest transmission power loss. Further, the length of the antenna 21 can be set so that the maximum electric field strength can be obtained by manually operating the antenna elevating key 35 while the user visually checks the screen display on the matching state display LCD 34.

[0024]

As is apparent from the above description, according to the antenna control type receiving apparatus of the present invention described in claims 1 and 3,
When the reception frequency is variably set, the received electric field strength data is stored, and the length of the antenna element is controlled so that the electric field strength is maximized while being read. As a result, the length of the antenna exactly matches the reception frequency, and reception can be performed favorably at the maximum electric field strength.

According to the antenna control type receiver of the second aspect, when the selection switch operated by one touch is depressed, reception control is performed at that frequency, and the read control time / electric field strength. Based on the data, by the control signal of the time to set the antenna element at the time of maximum extension or the length at the time of minimum contraction to the maximum electric field strength,
Since the length is set, it is possible to set the antenna element at the reception frequency once received, with one touch.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an antenna-controlled receiver according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of an operation of the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional antenna-controlled receiver.

FIG. 4 is a flow chart showing a processing procedure of an operation by a preset key in a conventional example.

[Explanation of Codes] 21 Antenna 22 Antenna Elevator 23 High Frequency Amplifier 24 Mixer 25 Local Oscillator 26 Intermediate Frequency Amplifier 27 Wave Detector 28 Electric Field Strength Detector 29 Loop Filter 30 MPU 31 Frequency Operation Key 32 Frequency Display LCD 33 Memory 34 Matching State Display LCD 35 Antenna lift key

Claims (3)

[Claims] 1. An antenna element having a variable length, an antenna driving means for driving a variable length of the antenna element, a receiving means connected to the antenna element for receiving a variable received frequency, and the receiving means. A received electric field strength detecting means for detecting a received electric field strength at the antenna element based on a signal from the means; a storage means for storing received electric field strength detection data outputted from the received electric field strength detecting means;
When the receiving frequency is set by the receiving means, the received electric field strength detection data is stored in the storage means, and a control signal is sent to the antenna driving means so that the electric field strength becomes maximum while reading. An antenna control type reception device, comprising: a control unit that performs control for setting a length of an antenna element. 2. A storage unit for storing the control time and the electric field strength detection data for varying the antenna element length for each of a plurality of reception frequencies when the length of the antenna element is adjusted and set at the reception frequency. A plurality of selection switches corresponding to each reception frequency are provided, and when the selection switch is operated, the control means performs reception control at the frequency set in the operated selection switch, and from the storage means. Based on the read control time / electric field strength detection data, the antenna drive the control signal of the time to set the length of the antenna element at the time of maximum expansion or contraction to the maximum electric field strength. The antenna control type receiving device according to claim 1, wherein the antenna element length is set by sending it to the means. 3. The antenna control type receiving apparatus according to claim 1, wherein a screen display means is provided, and the fact that the antenna element is set to the maximum electric field strength is displayed on the screen by the screen display means.