JP2852132B2 - Radio selective call receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for antenna tuning means of a radio selective calling receiver. In particular, the present invention relates to an antenna tuning means for changing the antenna length of an antenna having a structure that can be worn on a human body.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional radio selective calling receiver.

Conventionally, as shown in FIG. 6, a radio selective calling receiver receives a radio calling signal by, for example, a band-type antenna 1 and capacitors 210 and 211 by an antenna tuning section 2A.
, 212 and the variable capacitor 213 to perform tuning and impedance matching, and to supply a radio paging signal to the radio section 3 most efficiently.

The radio signal is amplified by the radio section 3, mixed with an input signal from the local oscillator 4, frequency-converted, and an intermediate frequency signal is output. The amplitude of the paging signal converted into the intermediate frequency by the limiter 5 is limited, and DC detection is performed by the discriminator 6. When the output of the radio paging signal is small, the low-pass filter (LP
F) After passing through 7, the waveform is shaped by the comparator 8 and given to the signal control unit 9.

[0005] When a paging signal is input, the signal control section 9 establishes bit synchronization and frame synchronization by detecting a synchronizing signal. The signal control section 9 compares the subsequent individual paging signal with a paging number stored in the individual signal storage section 10 in advance. When comparison and collation are performed and it is determined that the call is made by itself, the speaker 11 notifies that there is a call.

[0006]

However, in such a conventional radio selective call receiver, an antenna tuning circuit is artificially provided for the reception frequency in order to optimize the reception sensitivity at a specific reception frequency. In addition, an antenna adjustment step has to be provided in manufacturing or repair, and there has been a drawback that this is one factor of cost increase. Further, mechanical adjustment of the variable capacitor and the like causes damage to components and poor adjustment, which has the disadvantage of reducing reception reliability.

[0007] Further, in this type of band type antenna, the antenna length changes due to the difference in the physical size of the human being worn,
There is a disadvantage that the antenna tuning is shifted due to the difference in the dielectric constant of the human body.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks. A radio selective call receiver capable of automatically adjusting an antenna tuning unit in response to a change in antenna length in a mounted state to always obtain the best tuning state. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION The present invention provides an antenna for receiving a radio call signal, tuning means connected to the antenna for tuning and impedance matching, and converting an output signal of the tuning means into an intermediate frequency signal. A wireless means, a detecting means for performing direct current detection of an output signal of the wireless means, and synchronizing based on an output signal of the detecting means, generating a clock signal, judging its own calling signal and notifying that there is a calling. A radio selective calling receiver comprising a signal control means, an AC / DC converting means for converting an output signal of the radio means into a DC signal corresponding to the amplitude thereof, and a plurality of AC / DC converting means corresponding to a voltage value of the converted DC signal. Digital conversion means for outputting a bit digital signal; and applying the control voltage to the tuning means based on the output digital signal to obtain the best tuning state. And an output control means for controlling the so that said AC to DC converter means, the output signal of the radio unit
Preamplifier that amplifies the signal, and the output signal of the preamplifier
To an AC / DC converter that converts
The output signal of the conversion unit is temporarily held and based on the clock signal.
And a hold unit that outputs the data.

[0010]

Further, according to the present invention, the digital conversion means includes a plurality of first resistors for dividing the input first reference voltage, an output signal of the AC / DC conversion means, and the divided first reference voltage. A plurality of comparators each receiving a voltage and outputting a digital signal of a plurality of bits can be included.

Further, in the present invention, the output control means includes an output control section for outputting a control signal based on the clock signal and an output signal of the AC / DC conversion means, and a plurality of output control sections for dividing an input second reference voltage. And a plurality of transfer gates that output the control voltage based on the divided second reference voltage and the output control signal.

[0013]

The elements of the tuning means achieve tuning and impedance matching by changing the reactance based on the input control voltage. The AC / DC converter converts the output signal of the wireless unit into a DC signal corresponding to the amplitude. The digital conversion means outputs a digital signal of a plurality of bits corresponding to the voltage value of the converted DC signal. The output control means applies the control voltage to the element based on the output digital signal and performs control so as to obtain the best tuning state.

As described above, it is possible to automatically adjust the antenna tuning section in response to a change in the antenna length in the mounted state, and to always obtain the best tuning state.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a radio selective calling receiver according to one embodiment of the present invention. In FIG. 1, a radio selective calling receiver includes an antenna 1 for receiving a radio calling signal, and an antenna 1.
And an antenna tuning unit 2 as tuning means for tuning and impedance matching, and a radio unit 3 as radio means for converting an output signal of the antenna tuning unit 2 into an intermediate frequency signal.
And a local oscillator 4 and a limiter 5, a discriminator 6, a low-pass filter 7 and a comparator 8 as a detecting means for DC-detecting an output signal of the radio unit 3, and synchronize a clock signal based on an output signal of the comparator 8 to generate a clock signal. The signal control unit 9 and the individual signal storage unit 10 and a speaker 11 are provided as signal control means for generating and judging a call signal of the own device and notifying that there is a call.

Here, the feature of the present invention is that the antenna tuning section 2 includes an element for tuning and impedance matching by changing reactance based on an input control voltage, and capacitors 201 to 203, and a radio section. 3
AC / DC converting means for converting the output signal of the DC signal into a DC signal corresponding to the amplitude thereof, digital converting means for outputting a digital signal of a plurality of bits corresponding to the voltage value of the converted DC signal, Output control means for applying the control voltage to the element based on the signal to perform control so as to obtain the best tuning state.

The antenna 1 has a structure that can be mounted on a human body, and has a characteristic that its inductive reactance component changes depending on the mounted human body.

Further, the above element is a variable capacitance diode 20.
4 to 206.

Further, the AC / DC converting means includes a radio unit 3
A preamplifier 12 that amplifies the output signal of the A / D converter, an AC / DC converter 13 that converts the output signal of the preamplifier 12 into a DC signal, and temporarily holds the output signal of the AC / DC converter 13 to the clock signal. And a hold unit 14 for outputting a signal based on the output.

Further, the digital converting means includes bleeder resistors 105 to 108 as a plurality of first resistors for dividing the first reference voltage input from the reference potential generating unit 15, an output signal of the hold unit 14, and the divided signals. And a plurality of comparators 101 to 104 each of which receives the first reference voltage and outputs a digital signal of a plurality of bits.

The output control means includes an output control section 16 for outputting a control signal based on the clock signal and the output signals of the comparators 101 to 104;
Bleeder resistors 114 to 118 as a plurality of second resistors that divide the second reference voltage input from the controller, and a plurality of control resistors that output the control voltage based on the divided second reference voltage and the output control signal. Transfer gate 109 ~
113 and

The operation of the radio selective call receiver having such a configuration will be described. FIG. 2 is a schematic diagram of the radio selective calling receiver of the present invention. FIG. 3 is a flowchart showing the operation of the radio selective calling receiver of the present invention. FIG. 4 is a time chart of each signal of the radio selective calling receiver of the present invention. FIG. 5 is a diagram showing a tuning state of a sine-tuning section of the radio selective calling receiver of the present invention.

In FIG. 1, a radio paging signal received by antenna 1 is supplied to radio section 3 by antenna tuning section 2 most efficiently. The radio unit 3 amplifies the input radio calling signal, mixes the signal with the local oscillation frequency signal supplied from the local oscillator 4, and performs frequency conversion. For example, it is output as an intermediate frequency signal of 455 KHz.

The output of the radio unit 3 is input to the limiter 5 and also to the preamplifier 12. The limiter 5 amplifies the input radio calling signal, limits the amplitude, and outputs the signal to the discriminator 6. Discriminator 6
Then, the signal whose amplitude is limited is subjected to FM detection and sent to the low-pass filter 7 as a calling signal. The low-pass filter 7 removes noise components from the ringing signal, and the waveform is shaped by the comparator 8 before being given to the signal control unit 9. In the signal control unit 9,
Synchronization is established by the synchronizing signal of the calling signal, and the individual calling signal following the synchronizing signal is compared with a calling number stored in the individual signal storage unit 10 in advance. Report that there was.

Next, the antenna tuning means of the present invention will be described.

The input stage of the radio section 3 is usually a high-frequency amplifier circuit using transistors, and the input impedance is capacitive. Therefore, the antenna 1 and the antenna tuning unit 2 are set to have inductive impedance and impedance matching is performed, and tuning is performed so that the signal received by the antenna 1 can be most efficiently input to the wireless unit 3. In this embodiment, the antenna tuning unit 2 is composed of the capacitors 201, 202, 203 and the variable capacitance diodes 204, 205, 206.

FIG. 2 is a perspective view of this embodiment. Fig. 2 (a)
2 shows an initial state, and FIG. 2B shows a mounted state. For example, the length l ₁ of the band-type antenna 1 to have become l ₂ changes, the tuning capacitance of the antenna tuning unit 2 changes. In the conventional receiver shown in FIG. 6, a variable capacitor 213 is provided so as to obtain the best sensitivity in the initial state shown in FIG.
In order to adjust the tuning point, the best tuning point cannot be obtained in the mounted state of FIG.

In the present embodiment, the intermediate frequency signal output from the radio unit 3 is amplified by the preamplifier 12 having a wide dynamic range in a range that does not saturate, and is supplied to the AC / DC converter 13. The AC signal input by the AC / DC converter 13 is rectified and smoothed and converted into a DC signal. The DC signal is temporarily held in the next-stage holding unit 14 and is sequentially output by a clock signal supplied from the signal control unit 9.

The voltages temporarily held by the hold unit 14 are input to comparators 101 to 104, respectively. Voltages obtained by dividing the reference voltage output from the reference potential generator 15 by the bleeder resistors 105 to 108 are also input to the comparators 101 to 104, respectively. Comparators 101 to 104 compare the voltage input from the hold unit 14 with the voltage output from the reference potential generation unit 15 and input after being divided by the bleeder resistance, and determine the voltage based on the voltage input from the hold unit 14 and the bleeder resistance. It is output as a digital signal of "H" or "L" according to the comparison value with the divided reference voltage. In the present embodiment, the data is converted into 4 bits, but the number of bits can be changed as needed.

4 output from the comparators 101 to 104
The bit binary signal is input to the output control unit 16. The output control section 16 outputs a control signal for controlling the transfer gates 109 to 113 in accordance with the input signals from the comparators 101 to 104 by a clock signal supplied from the signal control section 9.

The reference potential output from the reference potential generating section 15 is supplied to the transfer gates 109 to 113.
Are supplied respectively. Each transfer gate is controlled to be "on" or "off" by a control signal of the output control unit 16, and supplies a voltage corresponding to the operation to the variable capacitance diodes 204 to 206.

Since the capacitance values of the variable capacitance diodes 204 to 206 change according to the voltage applied to the cathode side,
The impedance of the antenna tuning unit 2 changes, and the radio unit 3
Output level changes.

Here, when the output level of the radio unit 3 becomes small because the antenna length changes and the tuning is shifted in the mounted state, the output control unit 16 controls the radio unit 3 in the initial state. The transfer gate is controlled so that the output is maximized, that is, the best tuning point is obtained according to the antenna length.

In FIG. 3, since tuning is performed in the initial state, the antenna length is not tuned in the mounted state. Therefore, the output level of the radio unit 3, that is, the output control unit
Since the input level of the output control unit 16 is small (S1),
Tries to raise the level.

For example, it is assumed that the antenna tuning in the mounted antenna length can be achieved in the direction in which the capacitance of the variable capacitance diodes 204 to 206 decreases, and the output level of the radio unit 3 increases. The output control unit 16 turns on the transfer gate (S2) and increases the voltage supplied to the variable capacitance diode (S3). Here, the transfer gate 113 is turned on in the order of the transfer gate 109. As the supplied voltage increases, the capacitance value of the variable capacitance diode decreases (S4), and the output level of the radio unit 3 increases.

That is, the level input from the comparators 101 to 104 to the output control unit 16 increases, and the level becomes maximum at the best tuning point with respect to the antenna length, but thereafter, the tuning point shifts and the level decreases. The output control unit 16 turns on the transfer gate from the direction in which the input level increases to the direction in which the input level decreases (S5). When the input level becomes low, the transfer gate is turned "off" (S
6) Reduce the voltage supplied to the variable capacitance diode (S7). Here, the transfer gate 113 is turned off in the order of the transfer gate 109. The capacitance value of the variable capacitance diode increases (S8), the tuning point of the antenna tuning unit 2 becomes the best again, and the input level becomes maximum.

However, if the capacitance value becomes too large, the tuning point shifts and the level becomes small. Therefore, the output control unit 16 stores the maximum input level value, and judges a change point by comparing the input level maximum value. Then, the transfer gate is controlled so that the tuning point becomes the best again so that the level becomes maximum (S10).

After that, since the output control unit 16 stores the maximum level value, it operates to maintain the maximum level point, that is, the best tuning point.

The operation described above is performed when there is a change in the antenna length in the mounted state. In addition, since the antenna length changes even when the antenna is returned from the mounted state to the initial state, the tuning point is changed according to the antenna length by the above-described flow. Will always give the best tuning point.

FIG. 4A shows the waveform of the intermediate frequency signal output from the radio unit 3, and FIG. 4B shows the signal waveform amplified by the preamplifier 12. What was tuned in the state of FIG. 2 (a) was out of tune because the antenna length changed in the mounted state of FIG. 2 (b), and thus the amplitude level detected initially was small. According to the flowchart shown in FIG. 3, since the tuning is performed, the amplitude level gradually increases, and finally, the amplitude level reaches the maximum and becomes stable. FIG.
FIG. 4C shows a waveform obtained by rectifying the AC signal in the AC / DC converter 13, further smoothing and converting the signal into a DC signal, and the waveform held in the hold unit 14 and input to each of the comparators 101 to 104. ). It is converted into a DC voltage corresponding to the amplitude level in FIG. V _S1 , V _S2 , V _S3 , and V _S4 are output from the reference potential generator 15 and bleeder resistors 105 to 10
8 indicates the reference voltage level input to each comparator. In FIG. 4D, there is a relationship of V _S1 <V _S2 <V _S3 <V _S4 . FIG. 4E shows the comparator 101, and FIG.
4 (g) shows the output waveform of the comparator 103, and FIG. 4 (h) shows the output waveform of the comparator 104.

In this embodiment, the transfer gates (109 to 113) are controlled by the output control unit 16 so that the maximum voltage is applied to the variable capacitance diodes 204 to 206 when all the 4-bit outputs of the comparator are "H". Controlled. FIG.
(i) indicates the voltage level applied to the variable capacitance diodes 204 to 206. V _St1 , V _St2 , V _St3 , V _St4 , V
_St5 is output from the reference potential generator 15 and the bleeder resistor 11
Transfer gates 109 to 113 after division by 4 to 118
Shows the reference voltage level input to the input terminal.

FIG. 4 (j) shows a change in the capacitance value of the variable capacitance diodes 204 to 206 due to the application of a voltage to the cathode side.
When the voltage is high, the capacity is small, and when the voltage is low, the capacity is large. Therefore, when the antenna length is changed, the tuning capacity of the antenna tuning unit 2 is changed by the change in voltage and capacity, so that optimum tuning and impedance matching conditions are obtained.

FIG. 5 shows the state of the antenna tuning unit 2 as viewed from the radio unit 3 according to this embodiment. FIG. 5A shows a state in which the antenna is not tuned in the mounted state.
Since the tuning is not achieved, the signal does not peak at the reception frequency F ₀ and the reception level is small. Variable capacitance diode 204 ~
206 to change the volume of the state where the tuning is rounded at the receiving frequency F ₀ in an antenna length in the mounted state is shown in FIG 5 (b).

However, the output controller 16 has not yet determined that FIG. 5 (b) is the best point, and the tuning is again shifted as shown in FIG. 5 (c) in order to further change the capacitance. However, it can be determined that the state shown in FIG. 5B is the best. That is, by storing the maximum value of the amplitude level (the best state of tuning), the capacitance is changed in the direction opposite to the conventional one, so that the tuning is again optimized as shown in FIG. To

The operation described above is performed instantaneously so as to follow the change of the tuning point.

[0046]

As described above, the present invention has an excellent effect that the antenna tuning section is automatically adjusted with respect to the change of the antenna length in the mounted state, so that the best tuning state can always be obtained. . In addition, there is an advantage that the number of adjustment steps at the time of manufacturing and repair can be reduced, cost can be reduced, and reliability can be improved without parts breakage and adjustment failure.

[Brief description of the drawings]

FIG. 1 is a block diagram of a radio selective calling receiver according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a radio selective calling receiver of the present invention.

FIG. 3 is a flowchart showing an operation of the radio selective calling receiver of the present invention.

FIG. 4 is a time chart of each signal of the radio selective calling receiver of the present invention.

FIG. 5 is a diagram showing a tuning state of an antenna tuning unit of the radio selective calling receiver of the present invention.

FIG. 6 is a block diagram of a conventional radio selective calling receiver.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Antenna 2, 2A antenna tuning part 3 Radio part 4 Local oscillation part 5 Limiter 6 Discriminator 7 Low-pass filter 8, 101-104 Comparator 9 Signal control part 10 Individual signal storage part 11 Speaker 12 Preamplifier 13 AC DC converter 14 Holder 15 Reference potential generator 16 Output controller 105-108, 114-118 Bleeder resistor 109-113 Transfer gate 201-203, 210-212 Capacitor 204-206 Variable capacitance diode 207 Resistance 213 Variable capacitor 301 Wireless Output waveform of unit 3 302 Output waveform of preamplifier 12 303 Rectified waveform in AC / DC converter 13 304 Output waveform of hold unit 305 Output waveform of comparator 101 306 Output waveform of comparator 102 307 Output waveform of comparator 103 308 Comparator Output waveform of 104 309 Applied voltage to variable capacitance diode 310 Change in capacitance value of variable capacitance diode 311 Chakujotai initial tuning state 312 tuning the best tuning condition l ₁ state 314 ultimately best tuning state 313 changes excesses tuning shifted in the process of changing, l ₂ antenna length V _S1 ~V _S4, V _St1 ~ V _St5 reference voltage level

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-262529 (JP, A) JP-A-61-251313 (JP, A) JP-A-4-150421 (JP, A) 173943 (JP, U) Shokai Sho 56-53844 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 1/18-1/24 H04Q 7/06-7/18

Claims (3)

(57) [Claims] 1. An antenna for receiving a radio calling signal, tuning means connected to the antenna for tuning and impedance matching, radio means for converting an output signal of the tuning means into an intermediate frequency signal, and A wireless means comprising: a detecting means for performing DC detection of an output signal; and a signal control means for synchronizing based on an output signal of the detecting means, generating a clock signal, judging its own calling signal, and notifying that there is a calling. In the selective call receiver, AC / DC converting means for converting an output signal of the wireless means into a DC signal corresponding to the amplitude thereof, and a digital signal for outputting a digital signal of a plurality of bits corresponding to a voltage value of the converted DC signal converting means, an output system for controlling based-out on SL control voltage to the output digital signal so as to the best tuning condition in addition to the tuning means And means, the AC to DC converter means, increasing the output signal of the radio unit
Preamplifier to be amplified and the output signal of this preamplifier
AC / DC converter for converting into a signal and this AC / DC converter
Output signal is temporarily held and output based on the above clock signal.
And a hold unit for performing a call. 2. An antenna for receiving a radio paging signal.
For tuning and impedance matching
Tuning means and an intermediate frequency signal output from the tuning means.
Wireless means for converting the signal into a signal, and an output signal of the wireless means.
Based on the output signal of the detection means
Synchronize and generate a clock signal to determine its own calling signal.
Signal control means for notifying that there was a call
In the radio selective calling receiver, the output signal of the radio means is converted into a DC signal corresponding to the amplitude.
AC / DC converting means for converting, and the converted DC signal
Output a multi-bit digital signal corresponding to the voltage value of
Digital conversion means and the output digital signal.
The control voltage is added to the tuning means based on the
Output control means for controlling a tuning state, wherein the digital conversion means includes a plurality of first resistors for dividing an input first reference voltage, an output signal of the AC / DC conversion means, radio paging receiver which comprises a plurality of comparators for outputting a digital signal of a plurality of bits to input a first reference voltage, respectively. 3. An antenna for receiving a radio paging signal.
For tuning and impedance matching
Tuning means and an intermediate frequency signal output from the tuning means.
Wireless means for converting the signal into a signal, and an output signal of the wireless means.
Based on the output signal of the detection means
Synchronize and generate a clock signal to determine its own calling signal.
Signal control means for notifying that there was a call
In the radio selective calling receiver, the output signal of the radio means is converted into a DC signal corresponding to the amplitude.
AC / DC converting means for converting, and the converted DC signal
Output a multi-bit digital signal corresponding to the voltage value of
Digital conversion means and the output digital signal.
The control voltage is added to the tuning means based on the
Output control means for controlling a tuning state, wherein the output control means outputs a control signal based on the clock signal and an output signal of the AC / DC conversion means, and a second input signal a plurality of second resistor for dividing the reference voltage, no, characterized in that it comprises a plurality of transfer gates for outputting the control voltage based on the divided second reference voltage and the output control signal <br/> Line selection call receiver.