Transponder system and method for measurement of separation

• US 7,119,736 B2
• Filed: 11/05/2002
• Issued: 10/10/2006
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Symeo GmbH (indie Semiconductor, Inc.)
• Original Assignee: Siemens AG
• Inventors: Heide, Patric, Vossiek, Martin, Nalezinski, Martin, Wiebking, Leif
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US10/495,104
• Publication Number:
  US 20050012653A1
• Time in Patent Office: 1,435 Days
• Field of Search: 342 29- 51, 342/118, 342/125, 342/175, 342187-197, 342 52- 58, 342/60, 342127-146
• US Class Current: 342/125
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/84 for distance determination by phase measurement
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

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.

Claims

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

${\mathrm{\omega <br><br>}}_{\mathrm{sw}}=\frac{2·<br><br>\mathrm{\pi <br><br>}·<br><br>B·<br><br>t}{T}$

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 (Δ

b=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

$s_{\mathrm{rx}}<br><br>\left(t\right)=s_{\mathrm{osz}}<br><br>\left(t-\frac{\mathrm{\tau <br><br>}}{2}\right)=\sin <br><br>\left({\mathrm{\omega <br><br>}}_{\mathrm{osz}}·<br><br>t-\left({\mathrm{\omega <br><br>}}_c+{\mathrm{\omega <br><br>}}_{\mathrm{sw}}\right)·<br><br>\mathrm{\tau <br><br>}+{\mathrm{\varphi <br><br>}}_o\right)$

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.