SE468030B - METHOD FOR AUTHORIZING A CLOSE SYNCHRONIZATION PROCESS FOR A DOUBLE-DIRECT COMMUNICATION BETWEEN A TRANSPONDER AND AN INTERROGATOR WHERE DIFFERENT FREQUENCIES MAY BE USED BEFORE COMMUNICATION BETWEEN THE INTERROGATOR AND TRANSPORTER - Google Patents

Description

468 10 20 25 30 35 030 2 of n fi croxsaw saw frequencies two microwave freewheels were transmitted from the interrogator, where a difference freewheel is a clock signal with the same frequency as the frequency of the clock signal when said communication is made to take place at lower frequencies.

The invention is described in more detail below, partly in connection with exemplary embodiments shown in the accompanying drawings, in which Figure 1 shows a simple blemish across an interregate and a transponder where relatively low frequencies are used - Figures 2 and 3 show signals at certain points in figure 1 - figure 4 resp. 5 shows a part of an interrogator resp. a transponder when Inikrovågsfrelwezuser is used - figure 6 shows a frequency diagram.

Figure 1 shows a communication theory fl c intended for relatively low frequencies.

This comprises an interrogator 1 and a transponder 2. The interrogator comprises a generator 3 arranged to generate two frequencies f1 and 1/2 f1, for example 114 kHz and 57 kHz. Furthermore, there is a phase modulator 4 arranged to modulate the frequency f1 with a phase shift of 0 ° / 180 ° according to the data to be separated from the interrogator to the transponder. The interrogator has a transmitter coil 5 which connects the modulated fl signal and the unmodulated 1/2 fl signal to a receiver coil 6 belonging to the transponder 2.

The signals received by the transponder n are routed to two rectifier bridges, where the fl signal via a high-pass or bandpass filter 7 is routed to a first rectifier bridge 8, and where the 1/2 fl signal is routed via a low-pass or bandpass filter 9 to a others in the ear bridge. In this case, a zero-wave directional fl signal is formed and a full-wave directional 1/2 fl signal, respectively.

The signals thus transmitted are conducted via the respective amplifiers 11, 12 to a D-type flip-flop circuit 13. The amplifiers are saturated amplifiers that provide an output signal in the form of a rectangular wave.

In figure 2 resp. Figure 3 shows three different signals in a voltage-time diagram. The signal fl can be plotted fl = cos (2., Tf1xt + 0 ° / 180 °), where figure 2a shows the signal at the phase position 0 ° and where figure 2b the signal is shown at the phase position 180 °. These signals appear at the input of the amplifier 11, where the appearance of the signal is of course dependent on the data which control the phase shifts in the interrogator and which are thus to be transmitted to the transponder. Figures 3a and 3b show the latter signals after the amplifier 11.

The signal 1/2 fl can be drawn 1/2 fl = sinurflxt). The signal according to Figure 2c appears at the input of the amplifier 12 and the signal according to Figure 3c at the output of the amplifier 12.

The flip-flop circuit 13 is supplied with the signal according to Figures 3a and 3b at its signal input and with the signal according to Figure 3c at its clock input. The flip-flop circuit is triggered by the positive edges of the clock signal (Fig. 3c). The flip-flop sets show a binary "1" for phase position 0 ° and a binary "0" for phase position 180 °. This means that the phase-modulated signal is demodulated without using a phase-locked loop for recovering the carrier frequency. The signal appearing at the output of the flip-flop circuit is output to circuits (not shown) for processing and / or storing data.

When from transponder to interrogator an unmodulated signal fl or 1/2 fl is transmitted and the other of the two signals is switched off in generator 3. (now, for example, the signal fl is transmitted from the interrogator, it comes in the transponder: note signal to constitute the transponder's clock. the non-response mttagza and the nelvavelslrilccaaefl - the signal is coupled to an amplifier 14 and an ice of the multiplier, which is multiplied by a sinusoidal signal having a frequency which is an integer fraction of fl, eg 1/2, 2, 4, etc. The signal from the multiplier pulse 15 is coupled to phase modulator 16, which is arranged to phase modulate the signal with a phase shift of 0 ° / 180 °, i.e. in a corresponding manner as described above.

The phase modulator is controlled by a modulator which modulates it with data whose bit length is synchronized with fl, so that each data bit is an integer number of carrier periods.

The thus phase-modulated signal is fed back to the coil 6 of the conveyor, the transmitted signal being received by a notch coil 17 in the interrogator.

The coil 17 is connected to a circuit breaker 18, to form a half-wave signal. The half-wave circulating signal is fed via a biased amplifier 19, at the output of which a square wave occurs, to the signal input of a D-type 20 flip-flop circuit. Thus, a digitized signal is applied to the signaling array. To the clock input of the flip-flop circuit, a carrier and phase reference digitized from the generator 3 is connected by means of an amplifier 21. As a result, at the output of the flip-flop circuit, the demodulated phase modulation appears in the same manner as described above for the flip-flop circuit 13.

Interrogatonzs receivers can be known possibilities for synchronous filtering, meaelväraesbiiai fi m over certain tiasintetveii one. used, the wine is given by the exact knowledge of the frequency of the return signal and the times of its growth.

According to Llppfinnirxgen, the described low frequency link may form part of a nükro åg rye doctrine om c if the frequencies used constitute subcarriers to a carrier wave of milorovave frequency.

In this case, the coil 5 of the interrogator is replaced by a microwave generator 28 and a microwave antenna 22. The microwave generator 28 is arranged to transmit two signals of microwave freewheel races, which are frequency modulated with the frequencies f1 and 1/2, respectively, by means of the previously mentioned generator 3. one is modulated with fl and one which is luodulated with 1/2 fl, as illustrated in Figure 6. The coil 6 of the transponder is replaced by an Intake microwave antenna 23 with a blender diode 24. ßlerneraieden down one after this frequencies f1 and l / 2 fl are present, which are fed to the above-mentioned filters 7.9. Furthermore, the coil 6 is also replaced by a reflecting microwave antenna 25 to which a nxodulator diode 26 is connected. This modulator diode is fed from the previously mentioned modulator 16, the modulation appearing as a sideband to the reflected microwave signal.

The coil 17 is replaced by a microwave antenna 27 and a homodyne receiver 31, which receiver has two channels for detecting sidebands to respective micro-rake carriers transmitted from the interrogator. When the modulation signal emitted from the modulator 16 has the frequency 1/2 fl and the transponder receives two unmodulated microwaves with the difference frequency fl, methods from the Swedish patent no. 8902808-8 are used to generate sidebands in the transponder with mutual azplitude ratios so that simple sidebands can be easily demodulated in the interrogator.

When the modulation signal emitted from the modulator 16 has the frequency 10 -Pm G '\ C, D CI) (JJ C) 5 N x fl, where N is an integer fraction, i.e. a fraction between two integers, the so-called cross-mixing, meaning that inconvenient sidebands belonging to one carrier are mixed with the other carrier. The intermediate frequency from the homodyne receiver 31 then becomes (N +/- 1) x f1, with zero points depending on the distance between the interrogator and the transponder not appearing in the received signal.

The gay animal receiver 31 is connected to the rectifier bridge 18 in the same way as the coil 17. To the gay animal receiver, the frequency of one milk wave signal is led from the small wave generator 28 via a conductor 29, this signal serving as a local oscillator. Via a conductor 30, the frequency fl is passed to the flip-flop circuit 20 clockwise.

It is thus clear that in the manner described above nan can obtain compatible links for both high and low frequency, at the same time as a clock signal is transmitted to the transponder and at the same time as the zeroing problem is avoided.

Claims (3)

10 15 20 25 30 030 Patent claims. 1. A method for providing a closed oxygen communication loop for a bidirectional female function between a transponder and an interrogator, where different frequencies can be used for competition between the interrogator and the transponder, characterized in that the communication between the interrogator (1) and the transponder ( 2) takes place by causing a clock signal to be transmitted from the interrogator and received in the transponder and vice versa, in order to control co-murmur in both years between the interrogator and the transponder, by causing sub-node layers of data to occur at a low frequency both 1) and transponder (2) takes place via microwave frequencies as via lower frequencies, by using two microwave rails frequencies from the interrogator when using microwave frequencies, where a slzilmaasfrelwerls constitutes a clock signal with the same frequency as the frequency of the clock signal. . Method according to claim, characterized in that when using microwave frequencies a low-frequency link is included as a so-called subset to a high-frequency doctrine working at microwave frequencies fl: by bringing the low-frequency doctrine to work with non-carrier scales to the high-frequency doctrine. Method method, characterized in that when a modulation signal emitted from a modulator (16) in the transponder (2) has the frequency N x fl, where N is an integer fraction, the so-called cross-mixing,: meaning that curved sidebands belonging to a carrier are mixed with a second carrier, whereby an intermediate frequency becomes (N +/- 1) x fl, with zero points depending on the distance between the interrogator (1) and the transponder (2) not appearing in a signal received by the interrogator. m,