JPH01219687A - Moving body discriminating apparatus - Google Patents

Abstract

PURPOSE:To realize a moving-body discriminating apparatus having a simple construction and being inexpensive, by a method wherein a query device emitting a non-modulated wave or a modulated wave is provided with a directional coupler which can be formed of a strip line. CONSTITUTION:Out of outputs of an oscillator 140 distributed in two by a directional coupler 130, a signal led to a first output terminal 132 is totally reflected by a PIN modulator 120a, returns to an isolation terminal 134 and acts as a local oscillation power of a mixer 150. On the other side, a signal led to a second output terminal 133 passes through a PIN modulator 120b and a non-modulated wave is emitted as a reading signal from an antenna 110b. Receiving this reading signal, a response device 2 modulates it with an internal discrimination code and re-emits same. The query device 1 receives this modulated wave by the antenna 110b and supplies it to the mixer 150 through the PIN modulator 120b and the directional coupler 130.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention transmits and receives data over a relatively short distance between a transmitting/receiving device serving as an interrogator and a transponder mainly housed in a moving body. This invention relates to improvements to mobile object identification devices.

<Conventional technology> In recent years, small-sized devices have been mainly installed in moving objects.

A simple type mobile object identification device that transmits and receives data between a response unit that is a lightweight and simple wireless terminal unit and an interrogator that has a transmitting and receiving function has been in the spotlight.

Possible uses for these include product management within a factory, gate management by having people with responsiveness, and room entry/exit management.

For example, when using it for production control in a factory, a transponder is attached to each part, with individual data such as part code numbers, processing procedures, transport routes, etc. on the production line input into the memory unit in advance. Interrogators should be installed at major points along the line. The interrogator emits radio waves to transponders installed on each part flowing on the production line,
As mentioned above, it reads the internal data, outputs control signals to control the flow of the line, and controls the production line according to each part. If such a mobile object identification device is used, it becomes possible to form a highly flexible production line, and its application range spans a wide range of fields.

Although the mobile object identification device to which the present invention is directed is highly profitable as described above, it has conventionally been configured as a system as shown in FIG.

In FIG. 4, l is an interrogator, 2 is a transponder, and the interrogator l is a transmitting/receiving antenna 110. Circulator 102
1 distributor 10-3. Oscillator 140° mixer 150. The transponder 2 includes a signal processing circuit 160, and a transmitting/receiving antenna 201. i modulator 202, demodulator 203. It is composed of a signal processing circuit 204.

From the interrogator 1, the unmodulated wave of fO generated by the oscillator 140 is divided into two by the distributor 103, one of which passes through the circulator 102 and is radiated to the transceiver antenna 110 and the transponder 2, and the other is the local oscillation source of the mixer 150. In the 0 responder 2, which is used as Interrogator l from the transmitting/receiving antenna 201
re-radiated to. The signal from the transponder received by the transmitting/receiving antenna 110 of the interrogator l is transmitted to the circulator 1.
02, the mixer 150 uses the oscillator 140'5 as a local oscillation source for homodyne detection, and the signal processing circuit 160 demodulates identification data.

On the other hand, when the transponder 2 receives a modulated wave from the interrogator l obtained by 0N10FF of the output of the oscillator, the signal is demodulated by the demodulator 203 and is used as a power start signal for the transponder 2 or as an internal signal. The signal is sent to the signal processing circuit 204 as a signal for writing to the storage device.

<Problems to be Solved by the Invention> As mentioned above, in the conventional system, a circulator is used as a means for sending the output of the oscillator inside the interrogator to the antenna, and supplying the received signal from the transponder to the mixer. However, this circulator is very expensive and has the disadvantage of increasing the cost of the entire system.

The present invention was devised in view of the above-mentioned points, and provides a mobile object identification device that improves the above-mentioned problems and includes an interrogator with a simple and inexpensive configuration that does not require an expensive circulator. The purpose is to

Means for Solving the Problems In order to achieve the above object, the present invention provides an interrogator that emits unmodulated waves or modulated waves, and an interrogator that emits unmodulated waves emitted from the interrogator. , modulates the unmodulated wave with identification data stored in an internal storage device and re-radiates it to the interrogator, and on the other hand, when the modulated wave is received, it is received from a transponder that demodulates the transmitted data from the interrogator. In the mobile object identification device, the interrogator includes an oscillator, a directional coupler, a mixer, a PINf adjuster, an antenna, and a signal processing circuit, and the input terminal of the directional coupler is connected to the oscillator. and connect the first and second output terminals to the first and second output terminals, respectively. second P
Connect to the IN modulator, connect the output terminals of the first and second PIN modulators to the first and second antennas, connect the mixer to the aisle terminal, and connect the mixer to the output terminal of the mixer. In the present invention, instead of an expensive circulator, a directional coupler that can be formed using an inexpensive strip line is used, so the configuration is simple and inexpensive. A mobile object identification device can be realized.

<Embodiment> Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration block diagram of an embodiment of the present invention.

In FIG. 1, 1 is an interrogator, 2 is a transponder, and the interrogator 1 has antennas 110a and 110b.

PIN modulators 120a, 120b, directional coupler 130
, oscillator 140. Mixer 150. It consists of a signal processing circuit 160.

A second example of a complete set of P I N modulators 120a and 120b is shown below.
Figure (shown in a3).

In FIG. 2(a), the PIN modulator includes DC cut capacitors 121, 121 . DC return element 122, high frequency choke element 123. PIN diode 124.1
25, and when the modulation signal applied from the terminal 12B through the high frequency choke element 123i is at a positive potential,
Since the PIN diode 124 is forward biased and the PIN diode 125 is reverse biased, there is a through between the input and output (between terminals 126 and 127), and the input power is passed through to the output terminal 1 with almost no loss.
27. On the other hand, when a negative potential is applied to terminal 128, PIN diode 124 is reverse biased and 125
Since it becomes a forward bias, the input impedance becomes large and becomes an input oven state, and the incident power is totally reflected and is not transmitted to the output terminal 1.27.

Therefore, with positive and negative voltages as shown in Fig. 2(c)E, 0N1
By applying a pulse signal that turns 0FF to the terminal 128 as a modulation signal, a more ASK (
Amplitude 5htft Keying)
I get a signal.

Note that the mixer 150 here includes an impedance modulator 151 . Mixer diode 152. Band rejection filter 1
Although a single-end mixer consisting of 53 is used, other types may be used.Next, the principle of operation will be explained.

First, if you want to read the identification code inside the transponder 2, enter the PIN
A negative voltage is applied to the modulator 120a, and a negative voltage is applied to the PIN modulator 120b.
A positive voltage is applied from the signal processing circuit 160 to . As a result, the PIN modulator 120a is in an input oven state, and the input signal is totally reflected, while the PIN modulator 1
20b is in a through state between input and output.

Therefore, among the outputs of the oscillator 140 that are divided into two parts by the directional coupler 130, the signal guided to the first output terminal 132 is totally reflected by the PIN modulator 120a and returns to the isolation terminal 134, and is sent to the local part of the mixer 150. Works as oscillation power. On the other hand, the signal led to the second output terminal 18B passes through the PINi adjuster 120b't- to the antenna 110.
Read from b.

An unmodulated wave is emitted as a signal. The transponder 2 receives this read signal, modulates it with an internal identification code, and
re-radiate. The interrogator l transmits this modulated wave to the antenna 110b.
and the PIN modulator 120b.

and is supplied to mixer 150 through directional coupler 130 .

In the mixer 150, it is mixed with the above local oscillation power,
After high frequency components are removed by band rejection filter 153, only the signal components are input to signal processing circuit 160, where the identification code is demodulated. Next, when starting the transponder 2 or writing to the internal storage device, P
A negative voltage is applied to the IN modulator 120b to turn it off, while the PIN modulator 20a is turned off as shown in FIG. 2(c).
A modulation pulse as shown by K is applied. As a result, an ASK signal as shown in FIG. 2(b) is emitted from the antenna 110a, and the transponder 2 demodulates this signal and uses it as a power start signal or a write signal.

As mentioned above, in this embodiment, the %l output terminal 132rC-
The PINf adjuster 120a is the same as the second output terminal 133.
The PIN modulator 120b is connected, but by reversing these, the PINg and modulator 12 are connected to the grJl output terminal 132.
0b to the second output terminal 133 and the same <PINf adjuster 12
A similar operation can be obtained by connecting 0a.

Although the antennas 110a and 110b may be of any type, for example, they may be combined with a patch antenna for both left and right polarizations as shown in FIG. By switching the plane of polarization with respect to the signal), the effectiveness is further increased and the degree of discrimination is also improved.

<Effects of the Invention> As explained above, according to the present invention, an expensive circulator is not required, so the cost is reduced, and the directional coupler can be formed with a microstrip line, so the configuration is simple. The effects of the present invention are extremely large, such as miniaturization.

[Brief explanation of the drawing]

[Figure 1 is a configuration diagram showing an embodiment of the present invention, Figure 2 (a)
6) is a diagram showing an example of the configuration of a PIN modulator.
A diagram showing the modulation waveform (ASK signal) by the modulator, the same figure (
c) Diagram showing the modulation pulse applied to the PIN modulator, %
FIG. 3 is a diagram showing a patch antenna for left and right circularly polarized waves, which is an example of an antenna configuration, and FIG. 4 is a configuration diagram showing a conventional mobile object identification device. l... Interrogator, 2... Responder, 201, 110a
. 110b...Transmitting/receiving antenna, 102...Circulator, 10B...Distributor, 120a,
120b...P/N modulator, 126a, 126b - input terminal, 127a, 127b - output terminal, 128a. 128b...Modulation signal input terminal, 121...DC
Cut capacitor, 122... DC return element, 123... High frequency choke element, 124.125.
...PIN diode, 130...directional coupler,
131...Input terminal, 132,183...Output terminal, 134...Inlay eye terminal, 140...
・Oscillator, 150...Mixer, 151...
Impedance switching device, 152... Mixer diode, 153... Band rejection filter, 160.2
04...Signal processing circuit, 202...Modulator, 2
03... Demodulator. Agent Patent Attorney Takeshi Sugiyama (and 1 other person) Figure 2 Figure 3g3 Figure 4

Claims (1)

[Claims] 1. An interrogator that emits an unmodulated wave or a modulated wave, and identification data stored in an internal storage device in response to receiving the unmodulated wave emitted from the interrogator; A mobile object identification device comprising a transponder that modulates an unmodulated wave and re-radiates it to an interrogator, and a transponder that demodulates transmitted data from the interrogator in response to receiving the modulated wave, the above-mentioned interrogator The device is an oscillator, a directional coupler, a mixer, and a P
It comprises an IN modulator, an antenna, and a signal processing circuit, the oscillator is connected to the input terminal of the directional coupler, and first and second PIs are connected to the first and second output terminals, respectively.
N modulator is connected, first and second antennas are connected to the output terminals of the first and second PIN modulators, a mixer is connected to the isolation terminal, and a signal processing circuit is connected to the output terminal of the mixer. A mobile object identification device characterized by being connected to.