Transponder system and method for measurement of separation
View Patent ↗Separation determination systems for determining the separation between a base station and a transponder, whereby the base station includes an oscillating signal source, for generating a signal and a transmission device for broadcasting the signal. The transponder includes a receiving device, for receiving the signal from the base station, an oscillator, for generating a signal which is phase-coherent therewith and a transmission device for broadcasting the phase-coherent signal. The base station furthermore includes a receiver device, for receiving the phase-coherent signal from the transponder and a separation determination device for determining the distance between base station and transponder. The system and components may be improved whereby the oscillator in the transponder is energized with the received signal in order to generate a quasi-phase-coherent signal.
1. Distance determination system for determining the distance from a base station (BS) to a transponder (TR), wherein
the base station (BS) has an oscillating signal source (OSZ B ) for generating a signal (s tx (t)) and a transmission device (ANT B ) for radiating out the signal (s tx (t)),
the transponder (TR) has a receiving device (ANT T ). for receiving the signal (e rxt (t)) from the base station (BS), an oscillator (OSZ T ) for generating a signal (s OSZ (t)) which is quasi-phase-coherent with the signal (e rxt (t)) from the base station (BS), and a transmission device (ANT T ) for radiating out the quasi-phase-coherent signal (s OSZ (t)), the oscillator (OSZ T ) excited with the received signal (S rxt (t)) into generating a quasi-phase-coherent signal (s OSZ (t)),
the base station (BS) has in addition a receiving device (ANT B ) for receiving the quasi-phase-coherent signal (s OSZ (t)) from the transponder (TR) and distance determination equipment (RMIX, FLT, DEMOD) for determining the distance (dist) between the base station (BS) and the transponder (TR), and
the distance determination equipment (RXMIX, FLT, DEMOD) in the base station (BS) has a mixer (RXMIX) for mixing the quasi-phase-coherent signal (s rxt (t)) received from the transponder (TR) and the instantaneous transmit signal (s tx (t)) to form a mixture signal (S mix (t)).
2. Distance determination system in accordance with claim 1 , wherein the distance determination equipment (RXMIX, FLT, DEMOD) is constructed to form the mixture signal (S mix (t)) given by
S mix ( t )=cos( t·ω sw +τ·(ω c +ω sw ))
where ω c is the central frequency of the base station oscillator (OSZ B ), ω SW is the modulation frequency of the transmit signal s tx (t) from the base station (BS), t is the time in the interval 0-Ts, and τ is the time for the propagation of the signals over the distance (dist) between the base station (BS) and the transponder (TR).
3. Distance determination system in accordance with claim 1 , wherein
the distance determination equipment (RXMIX, FLT, DEMOD) has demodulation equipment (DEMOD, GR, TP), for reducing or eliminating changes in the voltage of the mixture signal (S mix (t)), over the time interval (0–TS) between the measurement being switched on and switched off in the base station (BS), for the generation of a measurement signal (S mess (t)).
4. Distance determination system in accordance with claim 1 , wherein
the distance determination equipment (RXMIX, FLT, DEMOD) has demodulation equipment (DEMOD, ZFMIX, LO, TP) for mixing down the mixture signal s mix (t), in particular with a frequency near to or the same as a clock frequency (f mk ), to a frequency significantly lower than the clock frequency (f mk ), for switching the oscillator (OSZ t ) in the transponder (TR) cyclically on and off, followed by the filtering out of high-frequency components to generate a measurement signal (S mess (t)).
5. Distance determination system in accordance with claim 1 , wherein the distance determination equipment (RXMIX, FLT, DEMOD) is constructed to modulate the modulation frequency (ω SW ) of the transmit signal s tx (t) of the base station (BS), in particular such that
ω
sw
=
2
·
π
·
B
·
t
T
where T is a length of time over which the frequency is modulated across the bandwidth B.
6. Distance determination system in accordance with claim 1 , wherein the distance determination equipment (RXMIX, FLT, DEMOD) is constructed to form a resulting FMCW signal (s messfmcw (t)) as
s
mess
fmcw
(
t
)
=
cos
(
ω
c
·
τ
+
2
·
π
·
B
·
t
·
τ
T
+
π
·
B
·
t
·
T
s
T
)
·
sin
(
π
·
B
·
t
·
T
s
T
)
(
π
·
B
·
t
T
)
.
7. Distance determination system in accordance with claim 6 , wherein the distance determination equipment (RXMIX, FLT, DEMOD) performs a Fourier transformation of the amplitude-weighted measurement signal (s messfmcw (t)) in the frequency domain, so that edges of a left and a right sideband of at least one squarewave function which results determine the distance between the base station (BS) and the transponder (TR).
8. Distance determination system in accordance with claim 1 , wherein the distance determination equipment (RXMIX, FLT, DEMOD) is constructed for determining the distance (dist) from the measuring frequency (f mess ) which corresponds to a normal FMCW measurement frequency (Frequency Modulated Continuous Wave) displaced by a frequency component (Δb=B*Ts/(2 T)).
9. Distance determination system for determining the distance (dist) between a base station (BS) and a transponder (TR), wherein
the base station (BS) has an oscillating signal source (OSZ B ) for generating a signal (s tx )) and a transmission device (ANT B ) for radiating out the signal (s tx (t)),
the transponder (TR) has a receiving device (ANT T ) for receiving the signal (e rxt (t)) from the base station (BS), an oscillator (OSZ t ) for generating a signal (s OSZ (t)) which is quasi-phase-coherent with the signal (e rxt (t)) from the base station (BS), and a transmission device (ANT T ) for radiating out the quasi-phase-coherent signal (s OSZ (t)),
the base station (BS) has in addition a receiving device (ANT B ) for receiving the quasi-phase-coherent signal (s OSZ (t)) from the transponder (TR) and distance determination equipment (RMTX, FLT, DEMOD) for determining the distance (dist) between the base station (BS) and the transponder (TR),
the oscillator (OSZ T ) in the transponder (TR) is excited with the received signal (s rxt (t)) into generating a quasi-phase-coherent signal (s OSZ (t)), and
the transponder (TR) or the base station (BS), is constructed as an LTCC (Low Temperature Cofired Ceramic) module (LM), or making use of at least one LTCC module (LM).
10. Distance determination system for determining the distance (dist) between a base station (BS) and a transponder (TR), wherein
the base station (BS) has an oscillating signal source (OSZ B ) for generating a signal (s tx (t)) and a transmission device (ANT B ) for radiating out the signal (s tx (t)),
the transponder (TR) has a receiving device (ANT T ) for receiving the signal (e rxt (t)) from the base station (BS), an oscillator (OSZ T ) for generating a signal (s OSZ (t)) which is quasi-phase-coherent with the signal (e rxt (t)) from the base station (BS), and a transmission device (ANT T ) for radiating out the quasi-phase-coherent signal (s OSZ (t)),
the base station (BS) has in addition a receiving device (ANT B ) for receiving the quasi-phase-coherent signal (s OSZ (t)) from the transponder (TR) and distance determination equipment (RMIX, FLT, DEMOD) for determining the distance (dist) between the base station (BS) and the transponder (TR),
the oscillator (OSZ T ) in the transponder (TR) is excited with the received signal (s rxt (t)) into generating a quasi-phase-coherent signal (s OSZ (t)), and
the transponder is equipped with signal generation equipment (OSZ T , CLK/Sw) for generating an oscillator signal (s OSZ (t)) from a signal received by the transponder (e rxt (t)=s tx (t−τ/2)) using an oscillator (OSZ T ) and a switching facility (CLK/Sw) for switching the oscillator (OSZ T ) cyclically on and off, for generating an oscillator signal defined by
s
rx
(
t
)
=
s
osz
(
t
-
τ
2
)
=
sin
(
ω
osz
·
t
-
(
ω
c
+
ω
sw
)
·
τ
+
ϕ
o
)
where ω c is the central frequency of the base station oscillator (OSZ B ), ω SW is the modulation frequency of the transmit signal s tx (t) from the base station (BS), t is the time in the interval 0–Ts, and τ is the time for the propagation of the signals over the distance (dist) between the base station (BS) and the transponder (TR) and φ 0 is an arbitrary phase offset.
11. Distance determination system for determining the distance (dist) between a base station (BS) and a transponder (TR), wherein
the base station (BS) has an oscillating signal source (OSZ B ) for generating a signal (s tx (t)) and a transmission device (ANT B ) for radiating out the signal (s tx (t)),
the transponder (TR) has a receiving device (ANT T ) for receiving the signal (e rxt (t)) from the base station (BS), an oscillator (OSZ T ) for generating a signal (s OSZ (t)) which is quasi-phase-coherent with the signal (e rxt (t)) from the base station (BS), and a transmission device (ANT T ) for radiating out the quasi-phase-coherent signal (s OSZ (t)),
the base station (BS) has in addition a receiving device (ANT B ) for receiving the quasi-phase-coherent signal (s OSZ (t)) from the transponder (TR) and distance determination equipment (RMIX, FLT, DEMOD) for determining the distance (dist) between the base station (BS) and the transponder (TR),
the oscillator (OSZ T ) in the transponder (TR) is excited with the received signal (s rxt (t)) into generating a quasi-phase-coherent signal (s OSZ (t)), and
the transponder further comprises a modulator providing a modulation (f mk ) used for switching the oscillator (OSZ T ) in the transponder (TR) on and off, for transmitting
additional information from the transponder (TR) to the base station (BS).
12. Distance determination system for determining the distance (dist) between a base station (BS) and each of plural transponders (TR), wherein
the base station (BS) has an oscillating signal source (OSZ B ) for generating a signal (s tx (t)) and a transmission device (ANT B ) for radiating out the signal (s tx (t)),
each transponder (TR) has a receiving device (ANT T ) for receiving the signal (e rxt (t)) from the base station (BS), an oscillator (OSZ t ) for generating a signal (s OSZ (t)) which is quasi-phase-coherent with the signal (e rxt (t)) from the base station (BS), and a transmission device (ANT T ) for radiating out the quasi-phase-coherent signal (s OSZ (t)),
the base station (BS) has in addition a receiving device (ANT B ) for receiving the quasi-phase-coherent signal (s OSZ (t)) from the transponder (TR) and distance determination equipment (RMIX, FLT, DEMOD) for determining the distance (dist) between the base station (BS) and the transponder (TR), and
the oscillator (OSZ T ) in the transponder (TR) is excited with the received signal (s rxt (t)) into generating a quasi-phase-coherent signal (s OSZ (t)), and
each transponder is provided with a modulator having an individual modulation (f mk ) for switching the oscillator (OSZ T ) in the transponder (TR) on and off so that each transponder has a unique individual modulation different from the other individual modulations of the other transponders.