JPH04150421A - Selective radio call receiver - Google Patents

Abstract

PURPOSE:To automatically adjust an antenna tuning section to the best state in accordance with a receiving frequency by detecting the level of a radio call signal on the poststage side of the antenna tuning section and deciding the control signal to be given to the element of the antenna tuning section so that the level of the radio call signal can become the highest. CONSTITUTION:A series circuit composed of a fixed capacitor 201 and variable- capacity capacitor 203 is connected between one end of an antenna 1 and ground and a fixed capacitor 202 is connected between the other end of the antenna 1 and the input of a radio section 3. An antenna tuning section 2 is constituted by connecting a parallel circuit of three variable-capacity capacitors 204-206 between the connecting point of the capacitor 202 and antenna 1 and ground. When antenna tuning is not obtained against a receiving frequency, the output level of the section 3 becomes lower. In such a state, an output controlling section 16 adjusts the voltage applied across varactor diodes 203-206 by controlling transfer gates 109-113 so that the best tuned point can be obtained against the receiving frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio selective calling receiver, and more particularly to a radio selective calling receiver having a function of automatically adjusting an antenna tuning section to the best condition.

[Conventional technology]

A conventional radio selective calling receiver has a configuration as shown in FIG. In this radio selective call receiver, an antenna 1 receives a radio call signal, and after tuning and impedance matching is performed in an antenna tuning section 2 composed of fixed capacitors 210 to 212 and a variable capacitor 213, a radio section 3 receives a radio paging signal. Frequency conversion is performed by amplification and mixing with the local oscillation frequency signal from the local oscillator 4 to generate an IF frequency signal. This IF frequency signal is amplitude limited by a limiter 5 and DC detected by a discreet 6. Furthermore, since there is a lot of noise when the level of the radio calling signal is low, the output of the disc 6 is passed through a low pass filter (LPF) 7, the waveform is shaped by a comparator 8, and the signal is sent to the signal control section 9. In this signal control unit 9, when a call signal comes in, bit synchronization and frame synchronization are established by detecting a synchronization signal, and the subsequent individual call signal and own call number stored in advance in the individual number storage unit 10 are used. When the two match, it is determined that the call is for the user, and the speaker 11 notifies the user that the call has been made.

[Problem B to be Solved by the Invention] As described above, the conventional wireless selective calling receiver includes the variable capacitor 213 as a component of the antenna training section 2. Conventionally, an antenna adjustment step is provided in the process of manufacturing or repairing a receiver, and the capacitance of the variable capacitor 213 is adjusted using various measuring instruments.

This is to optimize the receiving sensitivity at a specific receiving frequency, but this antenna adjustment process has been a contributing factor to the increase in receiver manufacturing costs.

Further, this type of radio selective calling receiver often uses a super-hetero gain method, and by changing the oscillation frequency of the local oscillator 4, the reception frequency can be changed. However, when the reception frequency is changed, in the conventional radio selective calling receiver, it is necessary to readjust the antenna tuning section 2 accordingly, and the same problem as described above occurs.

The present invention has solved such conventional problems, and its purpose is to provide a radio selective call reception device having a function of automatically adjusting the antenna tuning section to the best condition according to the reception frequency of the radio call signal. The aim is to provide the opportunity.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a radio selective calling receiver that performs call notification by receiving a radio calling signal including a calling number assigned to itself in advance. An antenna tuning section that includes an element such as a variable capacitance diode whose electrical characteristics change according to the control signal is connected between the antenna that receives the radio paging signal and the radio section that amplifies the radio paging signal. , and level detecting means for detecting the level of the radio paging signal at a downstream side of the antenna tuning section, and changing a control signal given to the element of the antenna tuning section so that the level detection means detects the radio paging signal at a maximum level. and a control means for determining a control signal to be detected and thereafter continuing to apply the control signal to the element.

Further, a detection means for detecting an oscillation frequency of a local oscillator connected to the wireless section is provided, and the control means changes a change start point of the control signal according to the oscillation frequency of the local oscillator detected by the detection means. It has a structure.

[Function] In the radio selective calling receiver of the present invention, when a radio calling signal is received by the antenna, the level detecting means detects the level of the radio calling signal at the downstream side of the antenna training section, and the control means detects the level of the radio calling signal. , by changing the control signal applied to the element of the antenna same-day section, the level detecting means detects a radio paging signal of the maximum level, that is, the state of tuning and impedance matching of the antenna tuning section becomes optimal for the receiving frequency. After that, the control signal is determined and thereafter continues to be applied to the element.

Further, the detection means detects the oscillation frequency of a local oscillator connected to the wireless section, and the control means changes the change start point of the control signal according to the oscillation frequency of the local oscillator detected by the detection means.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

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

In the figure, a radio paging signal received by an antenna 1 is supplied to a radio section 3 via an antenna tuning section 2. The radio section 3 amplifies the input radio calling signal and mixes it with a local oscillation frequency signal supplied from the local oscillator 4 to perform frequency conversion, for example, 455 kHz.
outputs an IF frequency signal. The output of the radio section 3 is sent to the limiter 5 and also to the preamplifier section 12. The limiter 5 amplifies and limits the amplitude of the input radio calling signal, and then outputs it to the disc 6. The disc 6 performs FM detection on the amplitude-limited signal and sends it to a low-pass filter (LPF) 7 as a calling signal. Noise components are removed from the calling signal by this low-pass filter 7, and after waveform shaping is performed by a comparator 8, the signal is sent to a signal control section 9.

The signal control unit 9 establishes synchronization using the synchronization signal of the calling signal, and after the synchronization signal (compares and checks the individual calling signal with the calling number pre-stored in the individual number storage unit 10, and checks whether the two match). It is determined that the call is for the user, and the speaker 11 notifies the user of the call.

Next, the automatic antenna tuning function of this embodiment will be explained.

The input stage of the radio section 30 is usually a high frequency amplifier circuit using transistors, and the input impedance is capacitive. Therefore, the antenna 1 and the antenna training section 2 perform impedance matching using inductive impedance.
Tuning is performed so that the signal received by the antenna 1 can be most efficiently input to the radio section 3. Furthermore, it is desirable to be able to cover a relatively wide range of tuning points without replacing elements, and to eliminate the need for mechanical adjustment and to suppress damage to parts. Therefore, in this embodiment, a series circuit of a fixed capacitor 201 and a variable capacitor 203 is connected between one end of the antenna 1 and the ground, and a fixed capacitor is connected between the other end of the antenna 1 and the input of the radio section 3. 2
02 and connect this fixed capacitor 202 and antenna 1.
Connect three variable capacitors 2 between the connection point and ground.
By connecting the parallel circuits 04 to 206, the antenna tuning section 2
It consists of In addition, the variable capacitance diodes 203 to 2
A control voltage is applied to the cathode of 06 as described later.

Normally, the input impedance of the input stage transistor of the radio section 3 changes depending on the reception frequency. In the conventional radio selective calling receiver shown in FIG. 6, the tuning point is adjusted by a variable capacitor 213 in order to optimize the sensitivity, and if this is insufficient, the capacitance values of the capacitors 210 to 212 are changed. This ensures the tuning capacity and impedance at the desired frequency. In contrast, in this embodiment, the antenna tuning section 2 is adjusted as follows.

In FIG. 1, an F frequency signal outputted from a radio section 3 is amplified by a preamplifier section 12 with a wide dynamic range within a range that does not saturate, and is input to an AC-DC converter section 13. The AC signal input to the AC-DC converter 13 is rectified, smoothed, and converted into a DC signal. This DC signal is supplied to the hold section 14 at the next stage. The hold section 14 temporarily holds and outputs the input DC signal in synchronization with the clock signal supplied from the signal control section 9. The voltage output from the hold section 14 is applied to the comparator 10.
Each of the signals is input to one input terminal of 1 to 104. The reference voltage output from the reference potential generator 15 is input to the input terminals of the comparators 101-104 through the bleeder resistors 105-105.
The voltages Vsl to Vs4 divided by 08 are respectively input. The comparators 101 to 104 compare the voltage input to one input terminal and the voltage input to ten input terminals, and depending on the comparison result between the two, the voltage is set to logic °'1" or logic"o.
A total of 4-bit digital signals ra, b, c, d output from the comparators 101 to 104 are sent to the output control section I6. Here, each comparator 1
For 01 to 104, if the voltage J>u applied to one input terminal is greater than the voltage applied to ten input terminals, the outputs a - d are set to logic "1", otherwise they are set to logic "0", Vsl Since there is a relationship of >Vs2>Vs3>Vs4, when considering binary numbers (a, b, c, d), the magnitude of the value will depend on the magnitude of the voltage output from the bold section 14, that is, the output of the wireless section 3. This corresponds to the level of the radio calling signal that appears after frequency conversion.
In this embodiment, the level of the radio paging signal is converted into a 4-bit digital signal a-yd as described above, but the number of bits is not limited to 4 bits and can be changed as necessary. .

Now, the total 4-bit digital signals a%d output from the comparators 101 to 104 are input to the output control section 16 as described above. The output control unit 16 turns on transfer gates 109 to 113 (TGI to TG5) in response to input signals from comparators 101 to 104.
A control signal for controlling off is output in synchronization with the clock supplied from the signal control section 9.

Transfer gates 109 to 113 receive the reference potential output from reference potential generation section 15 through bleeder resistors 114 to 1.
Voltages VStl to Vst5 divided by 18 are supplied, respectively. Then, each transfer gate 109 to 113 is turned on or off by a control signal from the output control section 16.
By controlling the off state, a voltage corresponding to the control state is applied to the variable capacitance diodes 203 to 2 of the antenna training section 2.
06. In addition, in this embodiment, five types of voltages V
Although stl to Vst5 were used, more voltages may be used if necessary.

Since the capacitance values of the variable capacitance diodes 203 to 206 change depending on the voltage applied to the cathode side, the impedance of the antenna tuning section 2 changes, and as a result, the output level of the radio section 3 changes. Here, if the antenna is not tuned to the reception frequency, the output level of the radio section 3 will be low. In such a case, the output control unit 16 controls the transfer gates 109 to 113 to adjust the voltage applied to the variable capacitance diodes 203 to 206, and
In other words, the best tuning point for the receiving frequency is obtained.

FIG. 2 is a flowchart showing an example of the processing of the output control section 16 that performs such an operation, and the operation of the automatic adjustment control of the antenna training section 2 by the output control section 16 will be explained below with reference to the same figure. .

After the radio selective calling receiver shown in FIG. 1 is powered on and each part becomes operational, when a radio calling signal is received by the antenna 1, the radio part 3, the limiter 5. The disk drive 6, low-pass filter 7, comparator 8, and signal control section 9 operate as described above. At this time,
By detecting the input signal, the signal control section 9 alternately supplies clocks to the output control section 16 and the hold section 14,
The output control section 16 is caused to perform predetermined control, and the hold section 14 is caused to perform a hold operation.

When the first clock is input to the output control unit 16,
Turn off transfer gates 109 and 110, turn on other transfer gates 1-1], and turn on transfer gates 1 to 113.S1
), so that the control voltage Vst3 is supplied to the antenna tuning section 2. In this state, when the first clock is input from the signal control section 9 to the hold section 14, the control voltage Vs
The DC output corresponding to the level of the radio paging signal received by the antenna tuning unit 2 in the controlled state at t3 is held in the hold unit 14, and this held value is converted into a 4-bit binary number by the comparators 101 to 104. The output control unit 16 inputs the converted value and stores it in the level storage area Y (S2). Also, the control values (transfer game) 109, 110 are turned on and others are turned off) are stored in the internal control value storage area CNY (
S2). Then, the contents of the maximum level storage area MAX, which stores the value 0 in the initial state, and the contents of the level storage area Y are compared, and if Y < M A, X, step S5
If Y≧MAX, the process advances to step S4. here,
Normally, the input level never becomes zero, so Y〉MA
When the first clock is input, the output control unit 16 proceeds to step S4 and stores the current input level and control value in the maximum level storage area M A, X and the best control value storage area BST.
(Incidentally, the initial value of the best control value storage area BST is to turn off the I. Ransfurge 109 and 110 and turn on the others). Then, wait for the arrival of the next clock.

When the next clock is input from the signal control section 9, the output control section 16 also turns on the transfer gate 110.
L), so that the control voltage Vst2 is supplied to the antenna tuning section 2. In this state, when the next clock is input from the signal control section 9 to the hold section 14, the control voltage V
The DC output corresponding to the level of the radio paging signal received by the antenna tuning unit 2 under control in st2 is held in the hold unit 14, and the output control unit 16 outputs a 4-bit signal corresponding to this hold value. A binary value is input and stored in the level storage area Y, and the control value at that time is stored in the control value storage area CNY (S2). and,
The input level is compared with the previous input level stored in the maximum level storage area MAX, and step S4 or S is performed depending on the comparison result.
Proceed to step 5. That is, the determination result in step S3 is Y<MAX
If so, by increasing the control voltage applied to the antenna tuning section 2, that is, the variable capacitance diodes 203 to 20
By reducing the capacitance of variable capacitance diodes 203 to 206, the reception sensitivity of the radio calling signal has decreased, and in order to increase the reception sensitivity, the capacitance of variable capacitance diodes 203 to 206 must be increased, so proceed to step S5. On the other hand, if the determination result in step S3 is Y≧MAX, it means that the reception sensitivity of the radio paging signal has been increased by reducing the capacitance of the variable capacitance diodes 203 to 206, and Since the sensitivity may be further improved by reducing the capacitance of Then, in step S3, Y<M
Since it is determined that it is AX, the process proceeds to step S5 at that point.

Now, in step S5, when the next clock is input from the signal control section 9, the output control section 16 controls the transfer gates 109 to 113 to be sequentially turned off. For example, if the process moves to step S5 when up to the transfer gate 109 is turned on, the output control section 16 turns off the transfer gate 109 and turns on the others in step S5. In this state, when the next clock is input from the signal control section 9 to the hold section 14, the next clock signal corresponds to the level of the radio paging signal when received by the antenna tuning section 2 controlled by the control voltage Vst2. The DC output is held in the hold section 14, and the output control section 16 inputs a 4-bit binary value corresponding to this hold value and stores it in the level storage area Y, and also stores the control value at that time in the control value storage area CNY. (S6). Then, the input level is compared with the input level stored in the maximum level storage area MAX, and the process proceeds to step S8 or S9 depending on the comparison result. That is, if the determination result in step S7 is Y<MAX, the reception sensitivity of the radio paging signal is increased by decreasing the control voltage applied to the antenna tuning section 2, that is, by increasing the capacitance of the variable capacitance diodes 203 to 206. In this case, the input level stored in the maximum level storage area MAX is considered to be the maximum input level, so the best control value memory stores the control value that was able to obtain the maximum input level. Transfer gate 109 according to the memory contents of area BST.
The control in steps 113 to 113 continues thereafter. As a result, the antenna tuning section 2 is automatically adjusted to the best condition, and this condition is maintained thereafter.

If the judgment result in step S7 is Y≧MAX, the control voltage applied to the antenna tuning unit 2 is reduced, that is, the capacitance of the variable capacitance diodes 203 to 206 is increased, and the radio paging signal is received. The sensitivity has increased, and the variable capacitance diode 203~
Since the sensitivity may be further improved by increasing the capacitance of 206, the process returns to step S5 and the above-described operation is repeated. Then, by repeating the above-described operation, when the receiving sensitivity reaches its peak point, in step S7, Y<
Since it is determined that the value is MAX, the process proceeds to step S9 at that point, and the same operation as described above is performed.

The above-described automatic adjustment of the antenna tuning section 2 by the output control section 16 and the like does not need to be performed frequently, and only needs to be performed once in the following cases.

■ During manufacture and repair ■ When changing the receiving frequency Also, after turning on the power of the receiver, the automatic adjustment can be performed at any time, for example, it can be configured as follows.

(1) This is performed only once when the first radio call signal is received after the power is turned on. For example, a flag is provided in the signal control unit 9 or output control unit 16 that is reset when the power is turned on, and if this flag is reset, the flag is automatically adjusted and set when the first radio call signal is received. This can be achieved with a configuration like this.

(2) The receiver is provided with an instruction means such as an automatic adjustment start button, and when automatic adjustment is instructed by this instruction means, automatic adjustment is performed by receiving a radio call signal.

FIG. 3 is a block diagram of another embodiment of the present invention;
The same symbols as in the figure indicate the same parts, 17 is a frequency dividing section,
Reference numeral 18 represents an F-V conversion section, and reference numeral 9 represents a reference potential control section.

In FIG. 3, a radio calling signal received by antenna 1 is supplied to radio section 3 via antenna isothermal section 2. In FIG. The radio unit 3 amplifies the input radio calling signal and converts the frequency by mixing it with a local oscillation frequency signal supplied from the local oscillator 4, for example, 455kHz.
Outputs the IF frequency signal of z. The output of the radio section 3 is sent to the limiter 5 and also to the preamplifier section 12.

The structure and operation of the stages subsequent to the limiter 5 and the stages subsequent to the amplification section 12 are similar to those of the embodiment shown in FIG.

In this embodiment, the oscillation frequency signal of the local oscillator 4 is supplied to the radio section 3 and also to the frequency dividing section 17 . Normally, the oscillation frequency signal is a high frequency signal of about several tens of MHz, so this frequency dividing section 17
Divide the frequency into a low frequency signal of about This turbid low-frequency signal naturally changes when the oscillation frequency of the local oscillator 4 changes.

The frequency-divided frequency signal frequency-divided by °ζ in the frequency dividing section 17 is input to the F-V converting section 18 . The F-V converter 18 outputs a DC voltage of a level corresponding to the input divided frequency signal. This DC voltage is supplied to the reference potential control section 19. The reference potential control section 19 controls the setting of the reference voltage generated by the reference potential generation section 15 based on the supplied DC voltage.

That is, the reference voltage is increased or decreased. The subsequent operations of the output control section 16 and the like are similar to those in the embodiment shown in FIG.

As described above, when the reference voltage generated by the reference potential generating section 15 goes up or down, the control voltages Vstl to Vst,5 generated by the bleeder resistors 114 to 118 and the transfer gates 109 to 113 change up and down. Therefore, the output control unit 16 controls the control voltage at the start point of the change (sweep) (in the above example, Vst).

3) can be changed to a level that is expected in advance with respect to changes in the receiving frequency, and the optimum control voltage can be quickly determined.

In this embodiment, the change start point of the control voltage is raised or lowered by raising or lowering the reference voltage generated by the reference potential generating section 15, but the configuration of the bleeder resistors 114 to 118 and the transfer gates 109 to 113 allows a wide range of control. If the voltage can be covered, the reference potential of the reference potential generation section 15 is kept constant, and the transfer gate is turned on by the C output control section 6 at the sweep start point, that is, at the time of the start of the sweep, according to the output of the reference voltage control section 19. You may also change the .

Note that when the reference voltage generated by the reference potential generation section 15 increases or decreases, in this embodiment, the bleeder resistor 10 is adjusted accordingly.
The reference voltages Vsl to Vs4 in Examples 5 to 108 are also changed, but the reference voltages VS1 to Vs4 are fixed.
It is also possible to leave it there.

FIG. 4 shows an example of signal waveforms at various parts in the embodiment shown in FIGS. 1 and 3. FIG.

301 in FIG. 3A is a TF frequency output signal waveform of the radio unit 3, and 302 in FIG. 303 in the same figure (C) represents a waveform obtained by rectifying an AC signal in the ACDC conversion unit 13, and after being further smoothed and converted into a DC signal, the signal waveform input from the hold unit 14 to each comparator 101 to 104 is This is 304 in FIG. 3(d).

Note that Vsl to Vs4 in FIG. 3(d) indicate reference voltage levels that are output from the reference potential generator 15, divided by the bleeder resistors 105 to 108, and input to the comparators 101 to 104. In the embodiment described above, these reference voltage levels Vsl to Vs4 change in response to changes in the local oscillation frequency.

4(e) is the output waveform of the comparator 101, 306 in FIG. 4(f) is the output waveform of the comparator 102, 307 in FIG. 4(g) is the output waveform of the comparator 103, and FIG. 308 indicates the output waveform of the comparator 104, respectively. In the previous embodiment, the output control unit 1 is configured such that the maximum voltage is applied to the variable capacitance diodes 203 to 206 when all of the total 4-bit outputs of the comparators 101 to 104 are logic "1"("H").
6 controls transfer gates 109-113.

309 in the same figure (i) is a variable capacitance diode 203 to 20
6 shows the voltage level applied to 6. Also, ■stl~V
st5 is output from the reference potential generation section 15 and is applied to each transfer gate 1 after being divided by the bleeder resistors 114 to 118.
Indicates the voltage level input to 09 to 113. In the embodiment of FIG. 3, these voltage levels Vstl to Vst5 change by changing the local oscillation frequency as described above.

Reference numeral 310 in FIG. 4(j) shows changes in the capacitance values of the variable capacitance diodes 203 to 206 due to voltage application to the cathode side. The higher the voltage, the smaller the capacitance, and the lower the voltage, the larger the capacitance. Therefore, the tuning capacitance of the antenna tuning section 2 is changed by this change in voltage and capacitance, so that optimal tuning and impedance matching conditions can be obtained.

FIG. 5 shows the tuning state of the antenna tuning section 2 according to the present invention. The figure (a) shows the receiving frequency F in the initial state.
It represents a state where synchronization at O is not achieved. FIG. 4B shows a state in which the capacitances of the variable capacitance diodes 203 to 206 are changed and tuning is achieved at the receiving frequency FO. However, the output control unit 16 is unable to determine at that point that the point shown in FIG. 4(B) is the best point, and since the capacitance is further changed, the tuning is shifted again as shown in FIG. At that point, it can be determined that the state shown in FIG. 4B is the best, and the capacitance is changed in the opposite direction to return to the state shown in FIG. This returned state is shown in FIG. 3(d), and the tuning is at its best. Furthermore, the reception frequency is Fh
.

Alternatively, Fig. 5(e) shows a state in which the best tuning can always be achieved depending on the reception frequency even if Fl changes.
(f).

The operations described above are performed instantaneously (for example, several msec to tens of msec) in order to follow changes in the tuning point.

〔Effect of the invention〕

As explained above, in the wireless selective calling receiver of the present invention, the antenna tuning section includes an element such as a variable capacitance diode whose electrical characteristics change according to a control signal, and the antenna tuning section is arranged on the downstream side of the antenna tuning section. detecting the level of the radio calling signal and determining a control signal to be applied to the element of the antenna tuning section so that this level becomes approximately the maximum;
It becomes possible to automatically adjust the antenna tuning section to the best condition according to the receiving frequency. Therefore, the antenna adjustment process in manufacturing or repairing the receiver can be eliminated, making it possible to reduce the manufacturing cost of the receiver. Further, when the reception frequency changes, the antenna tuning section is automatically adjusted to match the change, so manual adjustment of the antenna tuning section is not necessary even when the reception frequency is changed. In particular, by detecting the oscillation frequency of the local oscillator and changing the starting point during control signal sweep when the control means determines the optimal control signal, the optimal control signal can be determined even when the received frequency changes significantly. Furthermore, it becomes possible to reliably and quickly perform automatic adjustment of the antenna tuning section to match the changed receiving frequency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a flowchart showing an example of processing of the output control unit 16, FIG. 3 is a block diagram of another embodiment of the present invention, and FIG. 4 is a block diagram of another embodiment of the present invention. FIG. 5 is a diagram showing various states of the antenna tuning section 2, and FIG. 6 is a diagram of a conventional wireless selective calling receiver. . In the figure, 1... Antenna 2... Antenna tuning section 3... Radio section 4... Local oscillator 5... Limiter 6... Discrete 7... Low pass filter (LPF) 8 ... Comparator 9 ... Signal control section 10 ... Individual number storage section 11 ... Speaker 12 ... Preamplification section 13 ... A (, -DC conversion section 14 ... Hold section 15 . . . Reference potential generation unit 16 . 114-118...Bleeder resistance 109-113...Transfer gate 201.20
2...Fixed capacitors 203-206...Variable capacitor patent applicant
1 person from outside NEC Corporation

Claims (2)

[Claims] (1) In a radio selective calling receiver that performs call notification by receiving a radio calling signal that includes a calling number assigned to itself in advance, an antenna that receives the radio calling signal and a radio section that amplifies the radio calling signal are connected to each other. An antenna tuning section configured to include an element whose electrical characteristics change according to a control signal is connected between the antenna tuning section, and level detection means for detecting the level of the radio calling signal at a downstream side of the antenna tuning section. , a control means for changing a control signal applied to the element of the antenna tuning section to determine a control signal at which a maximum level radio call signal is detected by the level detection means, and thereafter continuing to apply the control signal to the element; A wireless selective call receiver comprising: (2) A detection means for detecting the oscillation frequency of a local oscillator connected to the wireless section, and the control means changes a change start point of the control signal according to the oscillation frequency of the local oscillator detected by the detection means. 2. The wireless selective calling receiver according to claim 1, having a configuration of: