JPS62208722A - Radio equipment - Google Patents

Abstract

PURPOSE:To attain the efficient information by taking the isolation between both input terminals of a directional coupler, that is, isolation between a demodulator and a modulator and using a circularly polarized wave to as to send lots of information with small size and simple constitution so as to avoid the interference of undesired reflected wave. CONSTITUTION:A signal being the combination of signals at both input terminals 6a, 6b in in-phase is extracted from one output terminal 6c of a directional coupler 6 and other output terminal 6d is isolated to a signal by applying two signals in opposite phase. A demodulator 8 is connected to one output terminal 6c of the directional coupler 6, a modulator 9 having terminals common to input/output is connected to other output terminal 6d, the demodulator 8 and the modulator 9 are connected respectively to a signal processing unit 10, a transmission circularly polarized wave antenna 2a for data write of the section 1 is used as the left rotatory circularly polarized wave antenna and a circularly polarized wave antenna 2b in common use for data read transmission/reception is used as a right rotatory circularly polarized wave antenna.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a method for transmitting and receiving data over a relatively short distance between a transmitter/receiver unit serving as a fixed station and a simple wireless terminal unit attached to a mobile body. The present invention relates to a wireless device for use in wireless communication.

<Prior art> In recent years, simple wireless devices that transmit and receive data between a lightweight, small, and simple wireless terminal attached to a mobile object and a transmitting/receiving device that serves as a fixed station have been attracting attention. There is.

These can be used in various fields such as product management in a factory, gate management by having people carry wireless terminals, and people/room exit management. This type of wireless devices that have been put to practical use can be divided into optical type devices and electromagnetic induction type devices based on the data transmission and reception medium.

<Problems to be Solved by the Invention> However, the optical type has a drawback that it cannot be used if an object that blocks light is interposed between the transmitter/receiver unit and the wireless terminal unit. On the other hand, electromagnetic induction systems have the problem of requiring a wide frequency band as the amount of information to be transmitted and received increases.

<Object of the Invention> The present invention was devised in view of the above-mentioned problems. It is an object of the present invention to provide a wireless device that has signal discrimination and is capable of efficiently transmitting information.

<Means for Solving the Problems> In order to achieve the above object, the wireless device of the present invention transmits data between a transmitter/receiver section serving as a fixed station and the transmitter/receiver section attached to a mobile object. .

a receiving wireless terminal section, and the transmitting/receiving device section;
a transmitting circularly polarized antenna that transmits a signal for writing data to the wireless terminal; and a circularly polarized wave that rotates in a direction opposite to the writing circularly polarized wave for transmitting a signal for reading data from the wireless terminal. and a circularly polarized antenna for transmitting and receiving data, and has two feed points arranged to excite the wireless terminal in directions perpendicular to each other, and the excitation phase between the two feed points is set to π/2. A transmitting/receiving antenna that generates circularly polarized waves by shifting the antenna, and two input terminals that are isolated from each other and are connected to each of the feeding points via feeding lines with the same line length, and the input voltage is equally divided. a directional coupler having four terminals with two output terminals for outputting signals and shifting the phase of each signal by π/2; a demodulator connected to each of the two output terminals of the directional coupler; The gist of this is a configuration that is composed of a modulator and a signal processor connected to the demodulator and the modulator, respectively, and transmits and receives at the same high frequency.

Effects> In the wireless device of the present invention having the above configuration, the radio wave transmitted from the transmitting circularly polarized antenna of the transmitting/receiving device section is received by the transmitting/receiving antenna of the wireless terminal section, and this received signal passes through the directional coupler. The signal is input to the demodulator through the signal and demodulated, and the data held inside the signal processor is rewritten according to this signal.

On the other hand, a circularly polarized radio wave that is transmitted from the transmitting/receiving antenna and rotating in the opposite direction to the transmitting circularly polarized wave of the transmitting antenna is received by the transmitting/receiving antenna of the wireless terminal, and this received signal is sent to the directional coupler. The modulated signal is input to the modulator via the signal processor, and is modulated by the output signal from the signal processor in the modulator, and this modulated signal is outputted from the transmitting/receiving antenna as a circularly polarized wave rotating in the same direction as that at the time of reception, and this modulated wave is received by the transmitting/receiving antenna of the transmitting/receiving unit and detected, thereby reading the contents of the data written in the signal processor of the wireless terminal unit.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, to explain the point of view of the present invention, high-frequency microwaves are extremely effective in transmitting a large number of 1-n broadcasts between a transmitting/receiving device and a wireless terminal section.

On the other hand, in order to simplify the entire device, it is necessary to use a single frequency for transmitting and receiving radio waves and to perform efficient information transmission with high signal discrimination. In order to achieve this objective, we focused on the plane of polarization, which is a plane that includes the electric field hector and the propagation direction in the electromagnetic waves of transmitted and received radio waves, and used stable circularly polarized waves as the transmitted and received radio waves. If this circularly polarized wave is generated while reducing the generation of unnecessary waves, it should be possible to have a high degree of signal discrimination that is less susceptible to the effects of multiple reflected waves, and to perform efficient information transmission.

FIGS. 1 to 3 show an embodiment that focuses on the above-mentioned points. As shown in FIG. 1, the wireless device of the present invention is a simple wireless terminal that transmits and receives data between a transmitter/receiver unit 1 serving as a fixed station and the transmitter/receiver unit l attached to a mobile body 3. The transmitting/receiving device section 1 includes a transmitting circularly polarized antenna 2a for transmitting a signal for writing data to the wireless terminal section 4, and a transmitting circularly polarized antenna 2a for transmitting a signal for reading data from the wireless terminal section 4. As is clear from the comparison of the arrows shown in FIG. A circularly polarized wave rotating in the opposite direction to the writing signal transmission circularly polarized wave W1 transmitted from the transmitting circularly polarized antenna 2a,
The modulated circularly polarized wave W3 from the wireless terminal unit 4 is a circularly polarized wave that rotates in the same direction as the readout signal transmission circularly polarized wave W2 with respect to the propagation direction. Then, when the mobile unit 3 approaches the transmitter/receiver unit 1 serving as a master station and reaches an area where data can be exchanged with each other, communication is possible.

Next, in FIG. 2 showing a specific example of the wireless terminal section 4, the antenna 5 for both transmitting and receiving purposes is composed of an antenna element such as a batch antenna formed on a dielectric substrate, and has two feeding points. It has 5a and 5b. Each of these feeding points 5a
, 5b, the element section is excited in directions perpendicular to each other as shown by the arrows in FIG. Circularly polarized waves are generated by excitation. The direction of rotation of this circularly polarized wave is determined depending on which feeding point 5a or 5b is leading in phase.

A directional coupler 6 made of a known hybrid ring is provided as power feeding means for feeding power to each of the feeding points 5a, 5b with a phase shift of π/2. To briefly explain the principle of the hybrid ring used as this directional coupler 6, it has four input/output terminals 6a to 6b, and each terminal 6a
~6b is set to a length of λg/4 with respect to the shortened wavelength λg on the substrate, as shown in FIG.
Each terminal 6a to 6d is matched with a specific characteristic impedance. In this state, by selecting appropriate values for the widths Wl and W2 of the lines between the terminals 6a to 6d,
For example, when power is supplied to the input terminal 6a, no output appears at the other input terminal 6b, and it is possible to extract power to the output terminals 6c and 6d, which have phases different from each other by π/2 and have the same amplitude.

Utilizing such a principle, power is supplied to one input terminal 6a, and the phase with respect to this supplied power is π/2.
When forward and equal amplitude power is supplied to the other input terminal 6b, isolation is achieved between both input terminals 6a and 6b, and the power supplied to the re-input terminals 6a and 6b is connected to one output terminal 6C. While the power is taken out in the same phase, the other output terminal 6d has a re-input terminal 5a,
Since the powers supplied to 5b are out of phase with each other and cancel each other out, no power is extracted. On the other hand, the other output terminal 6d
The power supplied to the output terminal 6C does not appear as power at one output terminal 6C, and equal amplitude power is taken out to the re-input terminals 6a and 6b. In this case, the other input terminal 6b has a power whose phase is π/2 ahead of the one input terminal 6a.

Therefore, in order to use the directional coupler 6 having such characteristics as a feed circuit for the antenna 5, the two terminals 6a and 5b of the directional coupler 6 are connected to the feed points 5a and 5b of the antenna 5, respectively. Feed lines of the same length? A, 7b are connected so that the electrical lengths between them are equal, and each feed line 7a, 7b of the same length connects each feed point 5a, 5b and each terminal 6a, 6b, respectively. are connected so that the phase does not change.

When connected in this way, when the antenna 5 receives a circularly polarized wave rotating to the left, one feeding point 5a of the antenna 5
Since the phase of the electromagnetic waves taken out at the other feeding point 5b lags the phase of the electromagnetic waves taken out at the other feeding point 5b by π/2, these two types of electromagnetic waves can be directed through the feeding lines 7a and 7b without changing their phase. Both terminals 6a of the sexual coupler 6
, 5b, one output terminal 6c of the directional coupler 6 receives a signal obtained by combining the signals of the re-input terminals 6a and 6b in phase, whereas the other output terminal 6d, the two signals are added in opposite phases to isolate the signal.

On the other hand, when the antenna 5 receives a circularly polarized wave rotating in the right direction, the phase of the electromagnetic wave taken out at one feeding point 5a of the antenna 5 is π/2 smaller than the phase of the electromagnetic wave taken out at the other feeding point 5b. Therefore, the other output terminal 6d of the directional coupler 6 receives a signal obtained by combining the signals from the re-input terminals 6a and 6b in phase, whereas the one output terminal 6C receives No signal is output because two signals are added in opposite phases. Conversely, the other output terminal 6d
13, no signal appears at one output terminal 6c, and the phase of the signal at one feeding point 5a of the antenna 5 lags the phase of the signal at the other feeding point by π/2. , a circularly polarized wave rotating to the right is transmitted.

Therefore, as shown in FIG. 2, a demodulator 8 is connected to one output terminal 6c of the directional coupler 6, and a modulator 9 having a common input and output terminal is connected to the other output terminal 6d. , the demodulator 8 and the modulator 9 are each connected to a signal processor 10, and the transmitting circularly polarized antenna 2a for data writing of the transmitter/receiver unit 1 is a leftward rotating circularly polarized antenna. , the transmitting/receiving circularly polarized antenna 2b for reading data is a clockwise rotating circularly polarized antenna.

Next, to explain the operation of the embodiment device having the above configuration, the transmitting polarized antenna 2a of the transmitting/receiving device section 1 has a constant amplitude in a plane perpendicular to the propagation direction as indicated by the arrow in FIG. A transmission circularly polarized wave W1 for a data write signal that rotates at a constant speed in the left direction is transmitted, and when this transmission circularly polarized wave W1 is received by the transmitting/receiving antenna 5 of the wireless terminal section 4, the antenna 5 Since the phase of the electromagnetic wave at one feed point 5a is delayed by π/2, the signal is outputted only from one output terminal 6c of the directional coupler 6 and input to the demodulator 8, and the signal is processed according to this demodulated received signal. Vessel 1
The data held inside 0 is rewritten.

On the other hand, a circularly polarized wave antenna 2b for both transmitting and receiving purposes of the transmitting/receiving device section 1
When the transmission circularly polarized wave W2 for rightward rotation data readout No. 18 is received by the antenna 5 of the wireless terminal unit 4, the phase of the electromagnetic wave at one feeding point 5a of the antenna 5 is is π from the phase of the electromagnetic wave at the other feeding point 5b.
/2, the signal is output only from the other output terminal 6d of the directional coupler 6, inputted to the modulator 9, and modulated by the signal from the signal processor 10 in the modulator 9. The modulated wave is The signal is output from the input/output common terminal of the modulator and input to the directional coupler 6. Therefore, as described above, no power appears at one output terminal 6c, and the re-input terminal 6a
, 6b. At this time, the phase of both output waves is delayed by π/2 at one input terminal 6a compared to the other input terminal 6b. Therefore, each feeding point 5 of the antenna 5
a.

The modulated wave excited by 5b is a circularly polarized wave w3 rotating in the right direction with respect to the propagation direction as shown by the arrow in FIG. The signal is received and detected by the single transmitting/receiving circularly polarized antenna 2b, and the data held inside the signal processor 10 is read.

It should be noted that the present invention is not limited only to the above-mentioned embodiments, and it goes without saying that various embodiments are possible as long as the scope of the claims is not excluded. For example, in the embodiment described above, a case has been described in which the left-handed circularly polarized wave W1 is used for writing data, and the right-handed circularly polarized wave W2 is used for reading data. If the modulator 9 is connected to both output terminals 6d and 6c of the directional coupler 6, contrary to the embodiment, the planes of polarization of the transmitted and received radio waves can be reversed. Furthermore, it goes without saying that the directional coupler 6 is not limited to the high frisodrink of the embodiment, but other directional couplers having the same function and having four terminals can be used.

Furthermore, the circularly polarized wave Wl for writing data and the circularly polarized wave W2 for reading data can be made to have the same frequency.

<Effects of the Invention> As detailed above, according to the wireless device of the present invention, the isolation between both input terminals of the directional coupler 6, that is, the isolation between the demodulator and the modulator, provides The generation of unnecessary waves is extremely low, and by using circularly polarized waves, interference from unnecessary reflected waves can be avoided, polarization loss is stable regardless of the orientation of the wireless terminal, and,
The influence of multiple reflected waves is also small. Therefore, it is possible to efficiently transmit and receive signals without reducing the degree of signal discrimination. Therefore, by being able to transmit and receive at a single frequency and by configuring the feeding circuit for circularly polarized wave generation of the antenna using a directional coupler with four terminals, the wireless terminal section has an extremely simple configuration and is lightweight. A small and inexpensive device can be obtained. Furthermore, a large amount of information can be transmitted by using high frequencies, such as microwaves. Moreover, if the frequency of each radio wave for writing and reading data is the same frequency, effective use of frequency resources can be achieved.

[Brief explanation of drawings]

Each drawing shows an embodiment of the wireless device of the present invention, FIG. 1 is an overall configuration diagram, FIG. 2 is a block diagram of a wireless terminal section of 1m, and FIG. 3 is an explanatory diagram of the operation of FIG. 2. . 1-Five parts of transmitting/receiving equipment 3-Mobile object 4/-Radio terminal part 5-Antenna 5a, 5b-
m-feeding point 6・unidirectional coupler 6a, 6b, 6c
, 6d--Terminal of directional coupler? a, 7b・-Feed line 8-Demodulator 9-Modulator 10-Signal processor Patent applicant Sharp Co., Ltd. agent Patent attorney Nishi 1) New construction 1 Figure 2 Figure 2 M L ---1---- −−−−−−−−−−−+
+ -1 Figure 3

Claims (4)

[Claims] (1) Consisting of a transmitter/receiver unit serving as a fixed station, and a wireless terminal unit attached to a mobile body that transmits and receives data between the transmitter/receiver unit, and transmits data to the transmitter/receiver unit and the wireless terminal unit. a transmitting circularly polarized antenna that transmits a signal for writing data; and a transmitting/receiving circular antenna that transmits a signal for reading data from the wireless terminal section using circularly polarized waves that rotate in the opposite direction to the circularly polarized waves for writing. a polarized antenna, and has two feeding points arranged to excite the wireless terminal in directions perpendicular to each other, and by shifting the excitation phase between the two feeding points by π/2, circularly polarized waves can be generated. A transmitting/receiving antenna that generates a a directional coupler having four terminals with two output terminals that output with the phase shifted by π/2; a demodulator and a modulator respectively connected to the two output terminals of this directional coupler; 1. A wireless device comprising a signal processor connected to a modulator and a signal processor connected to a modulator, respectively, and configured to transmit and receive at the same high frequency. (2) The wireless device according to claim 1, characterized in that data held within the signal processor is changed by a signal input from the directional coupler to the demodulator. (3) The received signal input to the modulator is modulated by the output signal of the signal processor, and the modulated wave is output to the directional coupler by also using the received signal input terminal of the modulator. A wireless device according to claim 1 or 2, characterized in that: (4) The wireless device according to any one of claims 1 to 3, wherein each signal input from the directional coupler to the demodulator and the modulator has the same frequency.