JPH08242118A - Planar antenna, its resonance frequency control method and radio communication equipment - Google Patents

Abstract

PURPOSE: To transmit/receive the communication signal of a wide band with a single and small planar antenna. CONSTITUTION: A radiation conductor 1 and a ground conductor (not illustrated) are arranged in parallel through a dielectric substrate (not illustrated), and what is called a microstrip antenna (MSA) 100 is formed. Plural slit shaped notches 4a-4g and 4h are provided for the radiation conductor 1. Switch elements 5a-5e and 5f having contact points in the radiation conductor 1 are provided so that they straddle the both sides of the respective notches among the arbitrary notches of the notches 4a-4h. Switch control lines 7a-7e and 7f from a control circuit 6 controlling conduction are connected to the switch elements 5a-5f.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna suitable for use in mobile communication, a resonance frequency control method thereof,
And a wireless communication device.

[0002]

2. Description of the Related Art As an antenna of a radio communication system such as satellite communication, especially mobile communication, a planar antenna having a simple and durable structure and a low profile is widely adopted. That is, FIG. 17 shows a configuration of a microstrip antenna as such a typical planar antenna. 17A is a plan view and B is a sectional view.

In FIG. 17, a radiation conductor 171 and a ground conductor 172 are arranged in parallel with a dielectric substrate 173 interposed therebetween. Further, a point 174 indicates a feeding point, and this feeding point 174
One end of the conductive pin 175 is connected to. Further, the other end of the conductive pin 175 penetrates the dielectric substrate 173 and the ground conductor 1
The power supply connector 176 is formed by being led out to the 72 side.
As the shape of the radiation conductor 171, a circular type is known in addition to the rectangular type shown in the figure.

[0004]

In such a planar antenna, due to the recent demand for miniaturization of communication devices, miniaturization of the shape of the antenna has been actively studied. For example, the following methods are known as general methods for reducing the size. (1) As the material of the dielectric substrate 173, a material having a large relative permittivity εr is used. (2) The thickness of the dielectric substrate 173 is reduced.

According to the method (1), the radiation conductor 17
The area of 1 can be reduced to reduce the size of the entire antenna. However, the method (1) has a drawback that the bandwidth of signals transmitted and received becomes narrower as the size becomes smaller, and the antenna gain also decreases.

According to the method (2), the antenna can be downsized in the thickness direction. In addition, the method (2) has an advantage that the material cost is reduced, the workability is simplified due to the thin substrate, and the manufacturing cost is reduced. However, the method (2) has the same drawback as the method (1) that the bandwidth is narrowed when the thickness of the substrate is reduced.

Further, as a method for miniaturizing such a planar antenna, (3) a method is proposed in which a slit-shaped cut 182 is formed in a radiation conductor 181 as shown in FIG.
(See Japanese Patent Application No. 48803, Japanese Patent Application No. 4-106928, etc.)
Have been. However, the method (3) also has a drawback that the bandwidth of signals transmitted and received becomes narrower as the size becomes smaller, and the antenna gain also decreases.

That is, in most of the conventional planar antennas as described above, the antenna gain becomes maximum at the antenna resonance frequency, and at frequencies away from the antenna resonance frequency, the antenna gain decreases due to the reduction of reflection loss at the antenna feeding point. Therefore, when applying such a conventional antenna to a wireless communication device, an antenna having a sufficiently wide bandwidth that covers the frequency band used by the system must be used. The miniaturization of was supposed to be hindered.

When one antenna is used for both transmission and reception, a wideband antenna whose bandwidth covers the transmission / reception frequency is required, and the restriction of the bandwidth prevents miniaturization of the antenna. It was

More recently, there has been an increasing demand for terminals that can access a plurality of wireless communication systems. For example, sharing of a terrestrial cellular telephone system with a low-orbit satellite communication terminal or sharing of a GPS receiver with another wireless communication system is required. Therefore, when configuring a terminal sharing such a plurality of wireless communication systems,
It is necessary to provide an antenna that covers the use frequency band of each communication system, or prepare a very wide band antenna that covers the use frequency band of all these communication systems. Therefore, the antennas used for these devices have become large, and as a result, there have been problems such as high price and large size of the terminal.

This application has been made in view of such a point, and the problem to be solved is that in the configuration of the conventional planar antenna, the size limitation of the antenna is hindered by the restriction of the bandwidth. It was said that.

[0012]

For this reason, in the present invention, the radiation conductor of the planar antenna is provided with a plurality of slit-shaped notches, and switch elements having contacts at both ends of the notches are provided. Is. Further, the switch element of this plane antenna is controlled according to the frequency of the communication signal. Further, a control means for controlling the switch element of such a planar antenna according to the frequency of the communication signal is provided.

[0013]

According to this, the resonance frequency of the plane antenna is changed by the conduction of the switch element, and the resonance frequency is sequentially changed by a single small plane antenna, thereby substantially transmitting and receiving a communication signal in a very wide band. It can be carried out.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, according to the present invention, in a planar antenna in which a radiation conductor and a ground conductor are arranged via a dielectric substrate, one or more slit-like cuts are formed in the radiation conductor, and the cuts are straddled. It is a planar antenna characterized in that a switch element having a contact point is provided between radiation conductors.

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a planar antenna according to the present invention. In FIG. 1, similar to FIG. 17 described above,
The radiation conductor 1 and the ground conductor 2 (not shown) are the dielectric substrate 3
A so-called microstrip antenna (hereinafter, referred to as MSA) 100 is arranged in parallel via (not shown).
Is formed.

The radiation conductor 1 has a plurality of slit-shaped cuts 4a, 4b, 4c, 4d, as shown in the drawing.
4e, 4f, 4g and 4h are provided. Further, the switch elements 5a, 5b, 5c, 5d, 5e and 5 having contacts to the radiation conductors 1 on both sides so as to straddle both sides of each of the notches 4a to 4h.
f is provided. Furthermore, these switch elements 5a-5
Switch control lines 7a, 7b, 7c, 7d, 7e and 7f from the control circuit 6 for controlling the conduction are connected to f.

Therefore, in such MSA 100,
It is apparent from the above-mentioned document that the antenna can be downsized by providing the radiation conductor 1 with a plurality of slit-shaped cuts 4a to 4h. That is, according to the above-mentioned document, the resonance frequency of the antenna is lowered by providing the slit-like notch in the radiation conductor of the MSA,
For example, it is stated that the shape of the antenna designed to have a half wavelength can be miniaturized.

Further, in the above-mentioned MSA 100, the switch element 5 is provided in the notch 4 of the radiation conductor 1. That is, FIG. 2 is a diagram showing a method of connecting with the switch element 5 by enlarging an arbitrary cut portion 4 of the radiation conductor 1 provided on the dielectric substrate 3. In FIG. 2, a switch element 5 is provided between the radiation conductors 1 on the dielectric substrate 3 in the notch 4, and both contacts of the switch element 5 are connected to the radiation conductors 1 on both sides. A switch control line 7 from a switch control circuit 6 (not shown) for controlling the conduction state is connected to the switch element 5.

This makes it possible to change the conduction state of the switch element 5 according to the output signal level of the control circuit 6 and change the resonance frequency of the antenna. That is, with this configuration, for example, if four binary switch elements 5 are provided in the notch 4, it is possible to set a maximum of 16 antenna resonance frequencies. And for example 1
When the antenna of this example is applied to a wireless communication system of a band of 6 MHz, an antenna having a bandwidth of 1 MHz is used as compared with a conventional antenna having a bandwidth of 16 MHz. Can be switched and used, which enables miniaturization of the antenna.

In the flat antenna of the present invention, the switch element 5 and the control circuit 6 are different from those of the conventional flat antenna.
However, if these elements and circuits are composed of semiconductor elements, the added amount is small enough to be ignored, and the size can be reduced as compared with the conventional planar antenna. Further, the positions where the switching elements 5 are connected and the number thereof are determined by the frequency band of the applied wireless communication system, the bandwidth per channel, the shape of the radiating conductor 1, the length of the notch 4, and the like. Further, in FIG. 1 described above, an example in which the slit 4 is provided in the rectangular radiation conductor 1 is shown, but the same applies to a circular radiation conductor.

Further, FIG. 3 shows a more specific embodiment of the planar antenna according to the present invention. 3A is a sectional view, and FIG. 3B shows a plan view seen from above. See also FIG.
3A shows a cross section taken along line XX ′ in FIG. 3B.
Further, in this embodiment, an example of the MSA 100 using a dielectric substrate having a thickness H = 1.6 mm and a dielectric constant εr = 3.5 is shown.

That is, in the sectional view shown in FIG. 3A, the radiation conductor 1 and the ground conductor 2 are arranged in parallel via the dielectric substrate 3. A point 8 indicates a feeding point, and one end of a conductive pin 9 is connected to this feeding point 8. Conductive pin 9
The other end of the power supply connector 10 penetrates the dielectric substrate 3 and is led out to the ground conductor 2 side to form the power supply connector 10.

Further, in the plan view of FIG. 3B, slit-shaped cuts 4a to 4h are provided in the radiation conductor 1 having a length La of 40 mm on each side, two locations on each radiation conductor side, that is, eight locations in total. Further, as shown in FIG. 4, all of these notches 4a to 4h have a width Gs = 2.0 mm and a length Ls = 1.
It is a 0.6 mm rectangular notch.

The four switch elements 5a-5d are
For example, both ends of the notches 4a to 4d at the positions shown in B of FIG. Note that, in FIG. 3B, the switch element portion is schematically shown for easy understanding of the drawing, but actually, as shown in FIG. 4, the switch element 5 is connected with both ends of the notch 4 as contacts. However, in this example, the switch element 5 is connected to the entrance of the notch 4. A specific configuration example of the switch element will be described later.

Further, in the MSA 100, the switch elements 5a to 5d are the switch control lines 7 from the control circuit 6.
a to 7d. Further, the control circuit 6 has a function of converting the resonance frequency information data into a switch control signal. That is, the control circuit 6 generates the appropriate switch control data from the resonance frequency information data.
1 and a level conversion circuit 12 for converting the output signal level of the logic circuit 11 into a signal level that enables switch control. As a result, the MSA 100 changes the antenna resonance frequency based on the resonance frequency information.

Then, in this MSA100, Table 1
And the resonance frequency for the conduction state of the switch element, V
The measured values of SWR and bandwidth (band where VSWR <2) are shown. Therefore, in this Table 1, the switch elements 5a-5
It can be confirmed that the antenna resonance frequency can be changed by the set value of the conduction state of d. That is, in this example, the variable range of the resonance frequency is 110 MHz. In this case, in the conventional MSA having the same size, the bandwidth is 17 MHz (equivalent to the case where all the switch states in Table 1 are off), and it can be confirmed that the present invention can realize a wide band.

[0027]

[Table 1]

Further, in the above-mentioned example, the position of the switch element 5 was connected to the entrance of the notch 4 as shown in FIG. 4. However, by changing the connection position of the switch as shown in the next measurement example, resonance can be achieved. The frequency can be changed. This indicates that the antenna resonance frequency can be adjusted at an appropriate frequency according to the applied communication system. That is, FIG. 5 shows an example of the measurement. This measurement example is for an antenna having the same shape of the radiation conductor 1 as shown in the above example,
Only the switch element 5a of FIG. 3 is connected to the notch 4a,
It shows changes in the resonance frequency when the connection position is changed.

In FIG. 5, the horizontal axis represents the switching element 5
Connection position X of a (X = 0 mm for the entrance of the slit, X =
10.6 is the resonance frequency when the switch is not connected), and the vertical axis is the antenna resonance frequency when the switch element 5a is turned on. Therefore, this FIG.
, The variable range of the resonance frequency of about 50 MHz is obtained by moving the position of the switch element 5a.

That is, as shown in this measurement example, according to the above-described embodiment, the resonance frequency can be changed by controlling the conduction of the switch elements 5a to 5d, and the band can be widened as compared with the conventional MSA of the same size. can do. Alternatively, in order to realize such a wideband antenna with a conventional MSA, it is necessary to use a low dielectric material or increase the substrate thickness, which causes problems in antenna size, material cost, and the like. is there.

Thus, according to the above-mentioned planar antenna, in the planar antenna in which the radiation conductor 1 and the ground conductor 2 are arranged via the dielectric substrate 3, one or more slit-shaped cuts 4 are formed in the radiation conductor 1. Do this along with this notch 4
By providing the switch element 5 having a contact between the radiation conductors 1 across the two, the resonance frequency of the planar antenna is changed by conduction of the switch element 5, and the resonance frequency is sequentially changed by a single small planar antenna. By
The communication signal can be transmitted and received in a substantially extremely wide band.

Further, some specific examples of the switch element 5 used in the planar antenna of the present invention will be described below.

First, FIG. 6 shows an example in which an FET is used as the switch element 5. In this figure, the source electrode of the FET 31 is connected to one end of the notch 4 formed in the radiation conductor 1 and the drain electrode is connected to the other end. And this FET3
The switch control line 7 from the control circuit 6 is connected to the gate electrode of 1. Further, in this case, the drain and source of the FET 31 are grounded in a DC manner, and the radiation conductor 1 is grounded via the choke coil 32 so as not to affect the antenna characteristics at a high frequency.

Therefore, in this circuit, by applying the control signal voltage Vg from the control circuit 6 to the gate electrode of the FET 31, the impedance between the drain and the source can be switched and the conduction of the switch element 5 can be controlled.
In this circuit, instead of the choke coil 32, a similar effect can be obtained by using a high impedance line 33 having a length of, for example, λg / 4 configured by a distributed constant element as shown in FIG.

In this circuit, the isolation between the drain and the source may be insufficient when the drain-source is off in a high frequency band. In that case, in order to improve the isolation, A, B, and B in FIG. As shown in each drawing of C, FETs 31a, 3
A switch may be configured by combining 1b and 31c and high impedance lines 34a and 34b having a length of λg / 4, for example. Note that Vg 'in the figure indicates a signal voltage obtained by inverting the control signal voltage Vg.

Further, FIG. 9 shows an example in which a diode is used as the switch element 5. In this figure, the anode of the diode 41 is connected to one end of the notch 4 formed in the radiation conductor 1 and the cathode is connected to the other end. Further, in this case, in order to supply the DC bias to the diode 41, it is necessary to separate both ends of the cut 4 in terms of DC. Therefore, as shown in the figure, the radiation conductor 1 is separated, and the gap 42 is narrowed so that it is sufficiently coupled in the high frequency band so that the antenna characteristics are not deteriorated. The choke coil 43 is provided on one side of the radiating conductor 1 from which the control signal path from the control circuit 6 is separated.
And is grounded via the choke coil 44.

Therefore, also in this circuit, by applying the control signal voltage Vd from the control circuit 6 to one of the separated radiation conductors 1, the impedance of the diode 41 is switched and the conduction of the switch element 5 is controlled. You can In this circuit, the choke coils 43, 44
Instead of the above, for example, the high impedance line 33 having a λg / 4 length shown in FIG. 7 may be used.

When a plurality of switch elements 5 are connected, as shown in FIG. 10, the radiation conductor 1 is DC-separated according to the positions of the respective diodes 41a, 41b, 41c, 41d, and chokes are provided for each. Coil 43
Control signal voltages Vda, Vdb, Vdc, Vdd, or the ground voltage are supplied via a, 43b, 43c, 43d, and 44.

Further, as shown in FIG. 11, the switch element 5 using the diode 41 can also be constructed by combining the high impedance lines 45a and 45b of λg / 4 length and the diode 46, for example.

The planar antenna of the present invention can also be a so-called monolithic antenna in which a semiconductor (for example, a GaAs substrate) is used for the dielectric substrate and the above switch circuit is directly formed on the semiconductor substrate. As a result, the manufacturing process of the antenna is simplified and the antenna cost can be reduced.

Further, the wireless communication apparatus of the present invention will be described below.

First, FIG. 12 shows an antenna control method and means when the planar antenna having the above-mentioned structure is applied to a radio communication apparatus using a frequency division multiple access system (hereinafter referred to as FDMA system). In FIG. 12, the MSA 100 having the above-described structure and the switch control circuit 6 are provided.
Then, the communication frequency information from the communication frequency setting circuit 51 of the communication device main body 50 is supplied to the control circuit 6.

That is, in the radio communication apparatus using the FDMA method, a base station sets a used frequency via a common channel, or a method of searching a free frequency band to set the used frequency is used. Therefore, the above-mentioned communication frequency setting circuit 51 shows a circuit having means for setting various use frequencies used for reception and transmission by the above method. Then, the signal from the frequency setting circuit 51 is supplied to the control circuit 6 and converted into a necessary switch control signal.

Further, at the time of reception, the signal received by the MSA 100 is supplied to the mixer 53 through the reception amplifier 52, and the local oscillation signal from the local oscillator 54 controlled by the signal from the frequency setting circuit 51 is mixed. Then, this mixed signal is supplied to the demodulation circuit 55, and the demodulated signal is supplied to the baseband section of the communication device main body 50.

At the time of transmission, a signal from the baseband section of the communication device main body 50 is supplied to the modulation circuit 56, this modulation signal is supplied to the mixer 57, and the local oscillator controlled by the signal from the frequency setting circuit 51 is supplied. The local oscillator signal from 58 is mixed. Then, this mixed signal is supplied to the MSA 100 through the transmission amplifier 59 and transmitted.

Therefore, in this device, the M of the above structure is
The SA 100 has, for example, as shown in FIG. 13, an antenna bandwidth narrower than the communication frequency bandwidth used in the applied wireless communication system, and the resonance frequencies are f ₁ , f ₂ , f ₃
... By switching to f _n-1 , for example, f ₀ ~
The entire communication frequency bandwidth used by the wireless communication system of f _n can be covered.

That is, when the frequency division multiple access method is used as the above-mentioned communication method, the conduction of the switch element of the planar antenna is controlled based on the frequency information of the received or transmitted signal so that the frequency of the received or transmitted signal is that of the planar antenna. It can be included in the resonance frequency. Therefore, in this device, communication can be performed using a small antenna, and the price and size of the terminal can be reduced.

Further, FIG. 14 shows an antenna control method and means when the planar antenna having the above-mentioned structure is applied to a radio communication apparatus using a frequency division duplex system and a half duplex system. In FIG. 14, the MSA 100 having the above structure and the switch control circuit 6 are provided. Then, the transmission / reception selection signal from the transmission / reception selection circuit 61 of the communication device main body 60 is supplied to the control circuit 6.

That is, in the radio communication device using the frequency division duplex system and the half duplex system, the reception band and the transmission band are set to different frequencies, and transmission / reception is switched by an external switch or a transmission / reception timing signal. There is. Therefore, in the transmission / reception selection circuit 61 described above, a circuit having means for switching between reception and transmission is shown. The signal from the transmission / reception selection circuit 61 is supplied to the control circuit 6 and converted into a necessary switch control signal.

In this case, the MSA 100 sets the antenna resonance frequency in two states by switching the states of the switches. The band has a band wide enough to cover the transmission band or the reception band of the wireless communication device. And the control circuit 6
Controls the states of the switch elements so that the wireless device covers the transmission frequency band of the MSA 100 when transmitting and the wireless device covers the reception frequency band of the MSA 100 when receiving the wireless device.

Further, a reception circuit 62 and a transmission circuit 63 are provided, and these circuits 62 and 63 are connected to the MSA 100 through a transmission / reception switching circuit 64 controlled by a signal from the reception selection circuit 61. As a result, when reception is selected, the signal from the MSA 100 is received by the reception circuit 6
2 to the baseband section of the communication device main body 60. When transmission is selected, the signal from the baseband unit of the communication device body 60 is transmitted to the MSA1 through the transmission circuit 63.
00 for transmission.

That is, when the frequency division duplex system and the half duplex system are used as the above communication system, the conduction of the switch element is controlled based on the transmission / reception selection signal, and the frequency of the reception signal at the time of reception and the frequency of the reception signal at the time of transmission are transmitted. The frequency of the signal can be included in the resonance frequency of the planar antenna. Therefore, in this device, it is possible to communicate using a small antenna,
It is possible to reduce the price and size of the terminal.

FIG. 15 shows the antenna control method and means of the transmission system when the planar antenna having the above-mentioned structure is applied to the radio communication system using the spread spectrum communication system using the frequency hopping system. In FIG. 14, the MSA 100 having the above structure and the switch control circuit 6 are provided. The PN series signal from the PN series generator 71 of the communication device main body 70 is supplied to the control circuit 6.

That is, in the radio communication apparatus using the spread spectrum communication method using the frequency hopping method, the transmission / reception frequency is changed by the PN sequence. Therefore, in the above-mentioned PN sequence generator 71, a circuit having means for controlling the change in the frequency of these transmission and reception is shown.
The signal from the PN sequence generator 71 is supplied to the control circuit 6 and converted into a necessary switch control signal.

In this case, the MSA 100 sets the two states of the antenna resonance frequency by switching the states of the switches. Then, it is assumed that the band has a band that respectively covers the transmission / reception band changed by the signal from the PN sequence generator 71. Then, the control circuit 6 respectively covers the transmission and reception bands changed by the signal from the PN sequence generator 71.
Controls the state of switch elements.

Further, in the transmission system, the signal from the baseband portion of the communication device main body 70 is supplied to the modulation circuit 72, this modulation signal is supplied to the mixer 73, and the PN sequence generator 71 is supplied.
The local oscillator signal from the local oscillator 74 controlled by the signal from is mixed. Then, this mixed signal is supplied to the MSA 100 through the transmission amplifier 75 and is transmitted.

That is, when the spread spectrum communication method by frequency hopping is used as the above communication method, the conduction of the switch element is controlled based on the PN series signal for frequency hopping, and the frequency changed according to the PN series is flat. It may be included in the resonance frequency of the antenna. Therefore, in this device, communication can be performed using a small antenna, and the price and size of the terminal can be reduced.

Further, FIG. 16 shows an antenna control method and means of a transmission system when the planar antenna having the above-mentioned structure is applied to a wireless communication apparatus sharing a plurality of wireless communication systems. In FIG. 16, the MSA 100 having the above-described structure and the switch control circuit 6 are provided. Then, a selection signal from the selection circuit 81 of the communication system is supplied to the control circuit 6.

That is, in a wireless communication device that shares a plurality of wireless communication systems, for example, when a system to be used is selected by an external switch or when a cellular phone and a satellite communication terminal are shared, the outside of the cellular service area. In some cases, the satellite communication system may be automatically selected when it goes out. The system selection circuit 81 shown here is a circuit that has such a system selection function and sends out the selection signal.

Then, for example, the communication device 82 of the first communication system and the communication device 83 of the second communication system are connected to the MSA 100 through the system switching circuit 84 controlled by the selection signal from the selection circuit 81. As a result, when the first communication system is selected, the MSA
100 is connected to the communication device 82, and the MSA 100 is connected to the communication device 83 when the second communication system is selected.

In this case, the MSA 100 sets the two states of the antenna resonance frequency by switching the states of the switches. The band has a band wide enough to cover the band of each communication system. Then, the control circuit 6 controls the MSA 100 so that the resonance frequency band of the MSA 100 covers the frequency band of the first communication system when the first communication system is selected, and the resonance frequency band of the MSA 100 when the second communication system is selected. The state of the switch element is controlled so that the resonance frequency band covers the frequency band of the second communication system.

That is, a plurality of arbitrary communication means are provided, the conduction of the switch element is controlled according to the selection of the communication means, and the frequency of the communication signal in the selected communication means becomes the resonance frequency of the planar antenna. Can be included. Therefore, in this device, communication can be performed using a small antenna, and the price and size of the terminal can be reduced.

Thus, according to the above-described wireless communication device, the radiation conductor and the ground conductor are arranged via the dielectric substrate to form one or more slit-shaped cuts in the radiation conductor, and to straddle the cuts. A planar antenna provided with a switch element having a contact between radiating conductors, and frequency information of a reception or transmission signal in any communication method, a transmission / reception selection signal, or a PN series signal for frequency hopping is used as a control signal of the switch element. A switch control circuit for converting the switch element is controlled by this control signal so that the frequency of each communication signal is included in the resonance frequency of the planar antenna. The resonant frequency is changed, and by changing the resonant frequency sequentially with a single small planar antenna. , It is capable of transmitting and receiving substantially very broadband communications signals.

[0064]

According to the present invention, the resonance frequency of the planar antenna is changed by the conduction of the switching element, and the resonance frequency is sequentially changed by a single small planar antenna, so that a communication signal of a substantially extremely wide band is obtained. You can now send and receive. In addition, this enables communication using a small antenna, which makes it possible to reduce the price and size of the terminal.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an example of a planar antenna to which the present invention is applied.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is a configuration diagram of a specific example of a planar antenna to which the present invention is applied.

FIG. 4 is an enlarged view of the main part.

FIG. 5 is a diagram for explaining the explanation.

FIG. 6 is a configuration diagram of a specific example of the switch element.

FIG. 7 is a diagram for explaining the explanation.

FIG. 8 is a configuration diagram of another example of a switch element.

FIG. 9 is a configuration diagram of another example of the planar antenna to which the present invention is applied.

FIG. 10 is a configuration diagram of another example of the planar antenna to which the present invention is applied.

FIG. 11 is a configuration diagram of another example of the switch element.

FIG. 12 is a configuration diagram of a specific example of a wireless communication device to which the present invention is applied.

FIG. 13 is a diagram for explaining the explanation.

FIG. 14 is a configuration diagram of another example of a wireless communication device to which the present invention is applied.

FIG. 15 is a configuration diagram of another example of a wireless communication device to which the present invention is applied.

FIG. 16 is a configuration diagram of another example of a wireless communication device to which the present invention is applied.

FIG. 17 is a configuration diagram of a conventional planar antenna.

FIG. 18 is a configuration diagram of the previously proposed planar antenna.

[Explanation of symbols]

 1 Radiation conductor 2 Ground conductor 3 Dielectric substrate 4a-4h Slit-like notch 5a-5f Switch element 6 Control circuit 7a-7f Switch control line 100 Microstrip antenna (MSA)

Claims (8)

[Claims] 1. In a planar antenna in which a radiation conductor and a ground conductor are arranged via a dielectric substrate, one or more slit-shaped cuts are formed in the radiation conductor, and the radiation conductor is straddled over the cuts. A planar antenna comprising a switch element having a contact between them. 2. The planar antenna according to claim 1, wherein the switch element is provided at a predetermined position between an entrance and an end of the cut. 3. A radiation conductor and a ground conductor are arranged via a dielectric substrate to form one or more slit-shaped cuts in the radiation conductor, and a contact is provided between the radiation conductors across the cut. A resonant frequency control method for a planar antenna, comprising a planar antenna provided with the switch element, and controlling the conduction of the switch element arbitrarily to change the resonant frequency of the planar antenna. 4. The resonance frequency control method for a planar antenna according to claim 3, wherein when the frequency division multiple access method is used as a communication method, the conduction of the switch element is controlled based on frequency information of a received or transmitted signal. A method of controlling a resonance frequency of a plane antenna, wherein the frequency of the received or transmitted signal is included in the resonance frequency of the plane antenna. 5. The resonance frequency control method for a planar antenna according to claim 3, wherein when the frequency division duplex system and the half duplex system are used as the communication system, the switching element is turned on based on a transmission / reception selection signal. A method of controlling a resonance frequency of a plane antenna, wherein the resonance frequency of the plane antenna is controlled so that the frequency of the reception signal during reception and the frequency of the transmission signal during transmission are included in the resonance frequency of the plane antenna. 6. The resonance frequency control method for a planar antenna according to claim 3, wherein when a spread spectrum communication method by frequency hopping is used as a communication method, the switching element is turned on based on a PN sequence signal for performing the frequency hopping. Is controlled so that the frequency changed according to the PN sequence is included in the resonance frequency of the plane antenna. 7. A radiation conductor and a ground conductor are arranged via a dielectric substrate to form one or more slit-shaped cuts in the radiation conductor, and a contact is provided between the radiation conductors across the cut. A planar antenna provided with a switch element having the switch element, and a switch control circuit for converting frequency information of a reception or transmission signal in any communication system, a selection signal of transmission or reception, or a PN series signal for frequency hopping into a control signal of the switch element. And controlling conduction of the switch element by this control signal,
A wireless communication device in which the frequency of each communication signal is included in the resonance frequency of the planar antenna. 8. The wireless communication device according to claim 7, wherein a plurality of arbitrary communication means are provided, the conduction of the switch element is controlled according to the selection of the communication means, and the communication in the selected communication means is performed. A wireless communication device in which the frequency of a signal is included in the resonance frequency of the planar antenna.