DE102006025436A1 - Method and device for generating frequency and / or phase modulated signals - Google Patents

Abstract

The invention relates to a method for generating frequency- and / or phase-modulated signals, in which an oscillator (SILO) for generating the signal (s <SUB> osz </ SUB> (t)) is excited switched and stimulating based a signal generated by a signal generator (SGEN) (s <SUB> inj </ SUB> (t)), wherein for exciting a harmonic signal (s <SUB> inj </ SUB> (t)) with a harmonic of the Signal Generator (SGEN) generated signal is used. The invention also relates to a device for generating frequency and / or phase modulated signals (s <SUB> osz </ SUB> (t)) with a stimulable oscillator (SILO), an on / off switch (SW) for interrupting and Restarting an oscillation of the oscillator (SILO) and a signal generator (SGEN) for generating a base signal as a basis for exciting the oscillator (SILO), wherein an element (NLE) for exciting the oscillator (SILO) a harmonic signal (s <SUB> inj < / SUB> (t)) is generated from the base signal of the signal generator (SGEN).

Description

The The invention relates to a method and a device for Generation of frequency and / or phase-modulated signals according to the above-mentioned Features of claim 1 and 6, respectively.

at modern wave-based measuring systems and communication systems, e.g. Automobile radars, technical or medical imaging systems, radio-based data transmission systems or radio location systems, radio identification systems increasingly very broadband signals are used. This very much broadband signals are referred to as UWB (Ultra Wide Band). The term UWB is defined according to the definition the US authority Federal Communications Commission (FCC) then commonly used if the signal bandwidth is either at least 20% of the center frequency the signal is or larger than 500 MHz is. Another trend that can be observed is in that the center frequency of wave-based measurement and communication systems higher and higher is, so increasingly very high-frequency systems are used.

One Problem with UWB systems is the cost-effective and power-saving generation the UWB signals in particular under the proviso that the generated signals Comply with the strict legal regulations in which frequency masks within which are the spectrum of generated UWB signals must lie. In the public Announcements by the FCC or the European Electronic Communications Committee (ECC) are such requests to the Spectral masks published.

The inexpensive and power-saving generation of the UWB signals is particularly difficult then if more complex modulation forms such as frequency and / or phase modulation, as they usually do used in modern measuring and communication systems, application should find. The difficulties arise because of the technical Means necessary for generating complex modulated signals are the more elaborate become, the higher the bandwidth of the signals is and the higher the center frequency of the Signals is.

It are approaches to the solution the difficulties. Modern wave-based measurement and communication systems with elaborate modulated signals are nowadays usually constructed so that in a lower frequency baseband generates the modulated signal and this modulated signal then with a fixed frequency oscillator and a mixer to the desired Center frequency is being mixed up. It is also known that this modulated Signal as baseband signal via Frequency multiplication or phase / frequency synthesizer. To generate the baseband signals are increasingly digital systems such as. Digital-to-analog converter or special DDS synthesizer (Direct Digital Synthesis). Most solutions is common that for broadband signals high digital clock rates or fast digital-to-analog converters and / or fast frequency dividers must be used. Power consumption and technological complexity are increasing with the clock rate significantly and thereby also the cost of this Elements.

Out For this reason, UWB systems work very often with simple pulsed ones Oscillators and very simple modulation types such as pulse position modulation or the amplitude modulation. Basic principles are e.g. in Terence W.Barrett "History of UltraWideBand (UWB) Radar & Communications: Pioneers and Innovators. "Simple UWB pulse signals are mostly based on one of the two following Species generated.

According to one first way of producing UWB pulse signals becomes the signal a fixed frequency RF oscillator (HF: high frequency) with a switch blanked with a switching signal. As a switch can also be a controllable Amplifier, an attenuator or a mixer can be used. In the simplest case is the Switch e.g. 200 ps closed and 20 ns open to pulses with a bandwidth of a few GHz.

According to one second way of producing UWB pulse signals is the oscillator or the oscillation itself switched on and off with the switching signal. This is e.g. known from "low-power Ultra Wideband Wavelets Generator With Fast Start Up Circuit "Barras, D., Ellinger, F .; Jackel, H .; Hirt, W. IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 54, NO. 5, May 2006, pages 2138-2145.

The second type has the advantage that the power consumption significantly is lower than the first type, since the first type of oscillator in the aforementioned switching example 99% of the time an unused Signal generated and consumed in this time pointless power.

adversely is the second type, that is the phase and often the frequency of the Signals usually is not under control since the oscillator is usually at every Turn on with a random one Phase starts.

In pulse radars, it is known to prevent this undefined oscillation that the oscillator is turned on and off with a switching signal having harmonics located in the frequency range of the oscillator. In this case, the oscillator always oscillates in synchronism with the phase of the harmonics of the switching pulses.

Both methods have in common that it is extremely complicated to form the spectra of the generated pulses targeted. Usually and in particular with the planned European approval regulations, it is necessary for the pulses to have a very defined envelope, for example a gauss-shaped or cos ^2- shaped envelope. Only under these conditions they remain in the spectral masks required by the regulatory authorities and generate extremely little power in the sidebands. However, such a targeted influencing of the amplitude within such short pulse times is technically very difficult to solve.

Out the reasons mentioned newer UWB systems are also increasingly using alternative more complex ones Modulation types such as OFDM modulation (OFDM: Orthogonal Frequency Divisional Modulation / Orthogonal Frequency Division Modulation). Hereby the baseband signals mostly with a digital-to-analog converter However, it is still necessary, the signals to a relative to restrict small bandwidth or to distribute the signals to different subbands. This is required because the digital-to-analog converter is the direct generation of signals with e.g. a bandwidth of several GHz not efficient allow. A widely discussed approach is e.g. the so-called UWB MB-OFDM, e.g. in "Ultra-wideband Communications: An Idea Time, "Liuging Yang, Giannakis, G.B., Signal Processing Magazine, IEEE Volume 21, Issue 6, Nov. 2004 Page (s): 26-54 "is displayed. Here is the available Spectrum in several bands divided and transmitted in each band, the information using OFDM modulation.

modern Methods for generating the frequency-modulated radar signals are e.g. in "Pichler, M .; Stelzer, A .; Gulden, P .; Seisenberger, C .; Vossiek, M., "Frequency-sweep linearization for FMCW sensors with high measurement rates ", IEEE Microwave Symposium Digest, 2005 IEEE MTT-S, San Francisco, USA, 12-17 June 2005 Page (s) 4 pp., 2005 ".

WO 05/098465 A2 describes a method for the synchronization of clock devices. US 2005030935 or WO 03/047137 A2 or DE 101 57 931 C2 describe a method and apparatus for synchronizing radio stations and a time-synchronous radio bus system.

DE 100 32 822 A1 respectively. US 6894572 B2 generally describe a device for generating an oscillator signal. In contrast to the normal coherence, a cyclically restored coherence is used, which is called quasi-phase coherence. A switched and quasi-coherent oscillating oscillator oscillating quasi-phase coherently with respect to an excitation signal is called a Switched Injection Locked Oscillator (SILO).

The The object of the invention is a method and a device for generating frequency and / or phase modulated signals such improve. In particular, a basic method and various devices or arrangements are proposed with which comparatively simple and very energy-efficient and / or power-efficient frequency and phase modulated UWB pulse signals can be generated.

These Task is solved by a method and a device for generating frequency and / or Phase modulated signals according to the above conceptual Features of claim 1 and 6. Advantageous embodiments are subject of dependent Claims.

Prefers becomes accordingly a method for generating frequency and / or Phase modulated signals in which an oscillator for generating the Signal is stimulated and stimulated based on a performed by a signal generator signal is carried out wherein for exciting a harmonic signal with a harmonic of the Signal Generator generated signal is used.

advantageously, is the harmonic signal from the base signal by means of a non-linear Elements generated.

The Harmonic signal is preferably in a feedback circuit of the oscillator fed. In the feedback loop of the oscillator, the harmonic signal is preferred in this case coupled, that the oscillator when switching by means of a On / off switch oscillates synchronously to the phase of the harmonic signal. The on / off switch is advantageous by means of a switching signal cyclically off and turned back on to generate a quasi-phase coherence.

According to the invention, a device for generating frequency and / or phase modulated signals with a stimulable oscillator, an on / off switch for interrupting and restarting an oscillation of the oscillator and a signal generator for generating a base signal as a basis for exciting the oscillator, wherein an element for exciting the oscillator, a harmonic signal from the base signal of Signal generator generated.

The Element for generating the harmonic signal is preferably a nonlinear one Element. The oscillator is advantageous in a radio location system used, in particular in a transponder of a radio location system used.

Of the Oscillator is preferably in an amplifier of a parent device or Arrangement used.

Advantageous are in particular such a method and / or such a device for generating the frequency and / or phase modulated signals Pulse durations between 10 ps and 100 ns pulse duration, in particular in the range of 100 ps to 10 ns pulse duration.

Prefers are in particular such a method and / or such a device, wherein the generated signal is a sampled signal having a sampling frequency according to the sampling theorem for obtaining payload information of the base signal in the harmonic signal is.

Advantageous is independent a transponder system with such a device for generating frequency and / or phase-modulated signals in a transponder, in particular in a transponder for position and / or distance determination of Transponders relative to a given point in space.

Especially become thereby a basic procedure and various devices or Arrangements proposed with which comparatively simple and very energy efficient and power efficient frequency and phase modulated UWB pulse signals can be generated. The procedures and arrangements but can also be very beneficial for high-frequency frequency and use phase-modulated narrowband systems.

exploited is the phase or frequency modulation thus of non-generic Impulse radars for known property of oscillators, preferably at power up to tune synchronously to a stimulus.

A Basic idea is thus based on the knowledge that an oscillator is in an unstable equilibrium in the ground state, and, when it is switched on, by a kind of foreign energy supply must first be encouraged to swing. Only after this initial Nudge will the feedback active, with which the vibration is maintained. Usually will for example, the thermal noise to such an initialization a resonant circuit used. That means that an oscillator with a random phase and amplitude will swing when turned on and then on its oscillated by its resonant circuit frequency oscillates. Will be in the oscillator at power up, however, according to the preferred embodiment injected an external excitation signal, the oscillator oscillates not by chance, but synchronous with the phase of the excitation signal. Depending on Frequency difference between the excitation signal and the oscillator signal and depending on the amplitude difference between the excitation signal and the oscillator signal this synchronicity remains more or less long. If the amplitude of the excitation signal is sufficiently large, it remains the synchronicity steadily received what is called "Injection Locking " becomes. This kind of coherent Synchronization is in B. Razavi, "A Study of Injecting and Locking in Oscillators "Proceedings of the IEEE Custom Integrated Circuits Conference, 21-24 Sept. 2003, pp. 305-312 described.

According to the preferred However, methods and devices or circuits are assumed that the amplitude of the excitation signal is very small relative to the Amplitude of the settled oscillator should be. In this Case, the oscillator oscillates synchronously, but then oscillates with its natural Frequency continues. In consequence, this causes the phase of the excitation signal and the phase of the oscillator signal steadily diverge over time. In this mode, a phase synchronism between the oscillator signal and the excitation signal over a longer one To maintain time, the oscillator or the oscillation must or for the oscillation necessary feedback condition cyclically switched off and then on again, so that the oscillator every time you turn on the phase of the Excitation signal starts. Thus, a quasi-phase coherence and is used a switched and quasi-coherent to an excitation signal oscillating oscillator as a switched injection Locked oscillator (SILO).

Advantageous The SILO principle is now extended in such a way that it saves energy and cost-effective Generation of phase / frequency modulated signals is used. The method or the basic idea of the following statements is a SILO on harmonics of a baseband signal to settle down. A decisive advantage exists here in that the amplitudes of the harmonics can be extremely small and therefore largely on amplifiers, In particular, can be dispensed with high frequency amplifier.

Significantly different is the present approach based on a switched oscillator SILO thus from the known injection-pulling or in jection locking Method for stabilizing non-switched oscillators. In injection locking methods, it is also known to synchronize oscillators to harmonics of a reference signal. In known injection pulling or injection locking oscillators, however, the oscillators do not operate switched but in continuous operation, which is why relatively large signals must be injected in order to ensure a phase-locked coupling. In addition, in injection pulling or injection locking oscillators, the frequency spacing between the injected signal and the oscillator signal must not be too large, since otherwise no synchronization can be achieved at all. Both disadvantages do not have the present preferred quasi-phase coherent oscillator approach. Extremely small excitation signals could be used.

Advantageous are also differently modulated signals with this arrangement e.g. Frequency-Hop modulated UWB signals or phase-coded UWB Signals for the purpose of data transmission in the o.g. UWB band to produce.

Very can be used advantageously the inventive principle and the UWB signal generators according to the invention in radio location systems. Transponder for radio location systems, such Use methods and arrangements are characterized by that the transponders are complex and modulable in the spectral mask specifically shapeable phase / frequency modulated pulse-shaped signals generate and still consume just about the same amount of power and about as inexpensive are like simple pulse-modulated systems.

Conveniently applicable are the devices described herein and equivalently thereto, in particular in or in combination with systems such as those described in US Pat US2005030935 Andreas Stelzer, Klaus Pourvoyeur, Alexander Fischer IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL.52, NO.12, PAGES 2664-2669, DECEMBER 2004, WO002005098465A2 and "Concept and Application of LPMA Novel 3-D Local Position Measurement System" are described.

In the article "Low-Power Ultra-Wideband Wavelets Generator With Fast Start-Up Circuit" Barras, D .; Ellinger, F .; Dachshund, H .; Hirt, W. IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 54, NO. 5, May 2006, pages 2138-2145 is a design for a switched UWB oscillator listed in which the arrangements are well suited according to the present basic principle. The oscillator shown in the article includes essential features necessary to implement an oscillator SILO and the presently preferred arrangements. In the article, as already in DE 100 32 822 A1 , also mentions the principal property of the phase-coherent excitability of a switched oscillator. Similar to a regenerative amplifier (see E. Insam, "Designing Super-Regenerative Receivers," Electronics World, April 2002, pp. 46 ff., 2002), however, the article does not suggest stimulating excitability to produce complex phase responses. or frequency-modulated signals, but primarily to influence the start-up time. In particular, both articles do not mention that switched oscillators according to the SILO principle are suitable for generating high-frequency phase and / or frequency-modulated UWB signals in the sense of a sampling process from sampled or harmonic waves of modulated base signals used for quasi-phase coherent excitation.

One embodiment will be explained in more detail with reference to the drawing. Based on various Fig. Illustrated various embodiments are the same with respect to designated components and functions are the same or equivalent, which is why specific explanations in each in this regard can be referenced in more detail. Show it:

1 1 schematically shows an arrangement of components for illustrating a basic principle of an arrangement or device for generating frequency and phase-modulated pulse signals,

2 two signal-frequency diagrams illustrating an effect using harmonics of a baseband signal to excite an oscillator,

3 an arrangement of components to

4 a first preferred arrangement of components for constructing a device with a DDF as a signal generator,

5 an arrangement of components with a digital-to-analog converter as the signal source,

6 by way of example an arrangement for constructing a frequency / phase modulatable UWB radio transmitter,

7 an arrangement for generating an amplitude-continuous signal by means of a pulsed SILO (Switched Injection Locked Oscillator / coupled oscillator with switched injection or excitation) and

8th an advantageous circuit for generating tion of a linearly frequency-modulated UWB signal.

1 shows the basic principle of a preferred circuit as a device for generating a frequency and / or phase-modulated signal s _osz (t).

The arrangement for generating frequency and phase-modulated pulse signals s _osz (t) comprises a signal generator SGEN, which generates as a merely exemplary signal source a frequency and / or phase modulated baseband signal.

the Signal generator SGEN downstream is a nonlinear element NLE, so that harmonics, i. Multiples of those contained in the baseband signal Frequencies are generated. On such an independent nonlinear Element NLE may be omitted if e.g. the signal generator SGEN itself is designed as an element with nonlinear properties is and generates harmonics.

The arrangement further comprises a filter BP, in particular bandpass filter, with which a certain harmonic wave is selected and the remaining bands, ie the band ranges of further fundamental and harmonic waves, are suppressed. The filter BP thus provides as a signal for an oscillator SILO a harmonic signal s _inj (t) of the base signal of the signal generator SGEN.

On the filter BP can be omitted, for example, if the downstream oscillator SILO itself has frequency-selective properties, ie e.g. a feedback transfer function R (ω) = A (ω) · β (ω) of the oscillator SILO has a corresponding bandpass behavior.

Accordingly, the arrangement further comprises the oscillator SILO as a switched and quasi-coherent oscillating to an excitation signal oscillator in the manner of a so-called Switched Injection Locked Oscillator (SILO). In this case, the harmonic _signal s _inj (t) is coupled into the feedback circuit of the oscillator SILO, so that the oscillator SILO during switching on synchronously to the phase of the harmonic _signal s _inj (t) oscillates. The point at which the harmonic _signal s _inj (t) forming an excitation signal is coupled into the feedback loop ultimately does not matter.

How out 1 As can be seen, the oscillator SILO is preferably a conventional oscillator, which may be realized in any embodiments. A special feature, however, is that switching means in the form of an on / off switch SW and a switching signal s _sw (t) are provided for switching the on / off switch SW. The on / off switch SW can be implemented, for example, by means of semiconductor technology or micromechanical elements. By means of the on / off switch SW and the switching signal s _sw (t) driving this, the oscillation of the oscillator SILO is cyclically switched off and on again in order to generate the quasi-phase coherence. The switching on and off of the oscillation can be carried out in various ways, for example by interrupting the feedback loop, reducing the loop gain or switching off the feedback amplifier.

For the suggestion of the oscillator SILO when needed extremely small excitation signals can be used. A advantageous condition to make this possible, there is only in that the amplitudes of the excitation signals are large compared to those of noise / interference signals are otherwise the oscillator preferably synchronous with the noise would swing.

According to first Experiments, a typical oscillator SILO can usually with excited quasi-phase coherent an excitation signal whose Level e.g. 80 dB less than the level of the oscillator SILO in the steady state. The theoretical limit eventually becomes only by the thermal noise or the Störsignalpegel in the oscillator given surrounding circuit. This quasi-phase coherent excitability with extremely small levels possible it to use harmonics of the baseband signal with very high order or largely on amplifiers or other power consuming active elements for high frequency signal generation to be able to do without.

When choosing the switching frequency and clock cycles as well as in the choice of the phase or frequency modulation preferably certain rules are observed to produce a desired phase profile in the oscillator signal. The reason for this is that the oscillator SILO oscillates at the frequency specified by its physical structure, ie in general it is not assumed that an injection locking is present, at least if the excitation signal is very small compared to the oscillator signal. The oscillator SILO thus oscillates in the general case with a different frequency than the excitation _signal.The phases of the two signals thus drift apart after being switched on as soon as the oscillator signal of the oscillator SILO becomes significantly larger than the excitation _signal in the form of the harmonic _signal s _inj (t). . to prevent this phase difference becomes too large, the oscillator SILO is then turned off at the latest again when the phase difference between the oscillator signal and to be generated signal s and the harmonic signal s is greater than the excitation signal _osz (t) _inj (t), as a preset threshold, then the osz will switch illator SILO turned back on, so he like derum oscillates synchronously to the excitation signal. This process is repeated cyclically. The threshold is application specific. Frequently phase deviations are acceptable which are clearly smaller than 90 °. Since the pulse durations usually have to be very short, for example for UWB signals-typically 100 ps-10 ns pulse length-the frequency deviation between the excitation signal and the oscillator signal can be relatively large without violating the above-mentioned condition. In many applications, eg with linear frequency-modulated signals, significantly larger phase deviations, ie longer switch-on times, can be tolerated, since the phase deviations generated by the SILO principle lead to deterministic and thus predictable / evaluable effects.

Also in the choice of the modulation of the excitation signal are preferably certain rules to be followed. The excitation signal must change its phase slowly enough. The maximum phase change allowed per time is ultimately given by the sampling theorem. For the derivation of the respective rules, the signal generation can be understood as a special type of scanning, from which can then be derived by signal theoretical considerations, the sampling condition, so that the generated signal s _osz (t) and the harmonic signal s _inj (t) or the this zugunde lying base signal carry the same information content.

The frequency multiplication by the use of the harmonics of the baseband signal of the signal generator SGEN causes in addition to the multiplication of the center frequency and a multiplication of the bandwidth of the modulation signal by the order of the harmonic wave. This effect is in 2 illustrated.

So that this effect does not lead to overlaps of adjacent harmonic bands or to ambiguities, it may be necessary to generate the final excitation signal via intermediate stages. An intermediate stage consists in each case of a filter, in particular bandpass filter BP1, BP2, which selects or suppresses a certain harmonic, and an upstream nonlinear element NLE1 or NLE2, which generates harmonics, as described in US Pat 3 is shown. Shown in 3 only the upstream of the oscillator components.

There, as shown, even extreme level losses, i. especially extremely small signals, can be tolerated, can also be the nonlinear Element NLE1, NLE2 of the intermediate stages to be a passive element. It is also advantageous to use an active element, to produce pronounced nonlinearities to be able to.

A favorable arrangement for execution in a parent arrangement shows 4 , The signal generator used here is a synthesizer DDS for direct digital synthesis. In extension to the circuit in 1 Preferably, an amplifier or directional coupler is placed behind the oscillator SILO. This can prevent that over the output of the oscillator SILO, which is indeed in the feedback loop, signals are injected, which would lead to an undesirable Anschwingverhalten. Downstream, the oscillator SILO an amplifier AMP be, if the gain of the self-amplifier forming oscillator SILO should not be strong enough.

In the embodiment according to 5 For example, a digital-to-analogue converter DAC is used for signal generation. When using a DAC digital-to-analog converter, it may be necessary to dispense with a non-linear element for generating harmonics. On the one hand, it can be exploited that a digital-to-analogue converter DAC, in which no desampling filter / reconstruction filter is used, generates a spectrum that repeats periodically at the sampling frequency. Also can be optionally exploited that a digital-to-analog converter DAC due to the quantization can be non-linear and generates harmonics itself.

6 shows a possibility of how based on the basic principle described a very simple mm-wave frequency / phase modulated UWB radio transmitter can be constructed. The baseband signal is generated for example with a digital frequency synthesizer as a signal generator. The synthesizer typically comprises a voltage-controlled oscillator VCO, a divider: N, a phase / frequency comparator PFD and, for example, a DDS, which generates the actual modulation or the comparison signal in the frequency synthesizer. The frequency multiplication takes place, as already shown, in two steps over a band at eg 20 GHz to the desired band at eg 60 GHz. For the generation of harmonics, nonlinear amplifiers NL AMP upstream of the filters BP can be used.

7 shows a possibility of how a pulsed oscillator SILO also an amplitude-continuous signal can be generated. As already stated, the oscillator SILO can be understood as a special form of sampling circuit. It is generally known that sampled, ie discrete-time signals by a desampling filter, here preferably a bandpass filter BP, can be converted into an amplitude-continuous signal. Stable scanning conditions and favorable filter characteristics can be set in a conventional manner.

8th shows an advantageous circuit for generating a linearly frequency-modulated UWB signal. A linear frequency modulated base signal is generated via the DDS and a synthesizer. It should be noted here that in the future, it will be cost-effective to generate signals in the low GHz range in a power-saving and technically simple way directly digitally with integrated CMOS circuits. Harmonics from the base signal thus generated are then generated via a nonlinear element NLE. The fifth harmonic, for example, is selected in the present example with the bandpass filter BP and the oscillator SILO thus excited quasi-phase coherent. The oscillator SILO is followed by a directional coupler RK for protection against external interference signals.

In order to produce a linearly frequency-modulated UWB signal, signal / system parameters are conceivable, such as generation of the linearly frequency-modulated base signal in the frequency range of 1.4-1.6 GHz, generating and filtering out the 5th harmonic, a center frequency of Oscillator SILO of 7.5 GHz, a clock cycle of the switching signal s _sw (t) from 1 ns on and 100 ns off at a bandwidth of the frequency modulation of 1 GHz and a modulation duration in the range of about 100 microseconds to about 100 ms.

The embodiment described above are not meant to be used in the invention or its applications of any kind.

Claims (12)

Method for generating frequency- and / or phase-modulated signals, in which - an oscillator (SILO) for generating the signal (s _osz (t)) is switched switched and - the excitation based on a signal generated by a signal generator (SGEN) signal (s for exciting a higher harmonic signal (s _inj (t) signal) generated by an harmonic of the (by the signal generator SGEN) is used -) that is performed _inj (t), characterized in that. Method according to Claim 1, in which the harmonic signal (s _inj (t)) is generated from the base signal by means of a nonlinear element (NLE). Method according to Claim 1 or 2, in which the harmonic _signal (s _inj (t)) is fed into a feedback loop of the oscillator (SILO). The method of claim 3, wherein in the feedback circuit of the oscillator (SILO), the harmonic signal (s _inj (t)) is coupled such that the oscillator (SILO) when turning by means of an on / off switch (SW) in synchronism with the phase of the harmonic signal (s _inj (t)) oscillates. Method according to Claim 4, in which the on / off switch (SW) is cyclically switched off and on again by means of a switching signal (s _sw (t)) in order to produce a quasi-phase coherence. Device for generating frequency and / or phase modulated signals (s _osz (t)) with - a stimulable oscillator (SILO), - an on / off switch (SW) for interrupting and restarting an oscillation of the oscillator (SILO) and - a signal generator (SGEN) for generating a basic signal as a basis for activating the oscillator (SILO), characterized in that - an element (NLE) for exciting the oscillator (SILO) a harmonic signal (s _inj (t)) (from the base signal of the signal generator SGEN ) generated. Apparatus according to claim 6, _wherein the element for generating the harmonic _signal (s _inj (t)) is a nonlinear element (NLE). Apparatus according to claim 6 or 7, wherein the oscillator (SILO) in a radio location system, in particular a transponder of a Radio location system is used. Device according to one of claims 6 to 8, wherein the oscillator (SILO) in an amplifier is used. Method according to one of claims 1 to 5 and / or device according to one of claims 6 to 8 for generating the frequency and / or phase-modulated signals (s _osz (t)) with pulse durations between 10 ps and 100 ns pulse duration, in particular in the range of 100 ps to 10 ns pulse duration. A method as claimed in any preceding claim, wherein the generated signal (s _osz (t)) is a sampled signal having a sampling frequency according to the sampling theorem for obtaining payload information of the base signal in the harmonic signal (s _inj (t)). Transponder system with a device according to one of claims 6 to 11 for generating frequency and / or phase-modulated signals (s _osz (t)) in a transponder.