An in-phase (I) and quadrature (Q) demodulator includes an input for receiving a signal, a reference frequency source, and a sampler connected with the input. The sampler includes a sampler strobe connected with the reference frequency source, and a non-linear transmission line (NLTL) connected with the sampler strobe. The NLTL receives a strobe signal generated by the sampler strobe and multiplies a frequency of the strobe signal to generate a sampler signal. When the sampler receives a signal from the input, the sampler is configured to generate and output an intermediate frequency (IF) signal using the sampler signal. A splitter of the demodulator separates the IF signal into an in-phase (I) component and a quadrature (Q) component. Mixers receive the I and Q components and generate I and Q output signals shifted 90 in phase.

Techniques related to signal processing include setting up a first operation mode or a second operation mode. In the first operation mode: providing a first analog signal to a first A/D converter by a first switch and a second analog signal to a second A/D by second switch, and converting the first analog signal to a first digital signal by the first A/D and the second analog signal to a second digital signal by the second A/D. In the second operation mode: demodulating a third analog signal to an in-phase signal and a quadrature signal by an I-Q-demodulator, providing the in-phase signal to the first A/D by the first switch, providing the quadrature signal to a second A/D by second switch, converting the in-phase signal to a third digital signal by the first A/D, and converting the quadrature signal to a fourth digital signal by the second A/D.

Methods and systems for generating a digital representation of the amplitude and phase of a bandpass signal are disclosed. The methods comprise filtering the bandpass signal with a bandpass filter, generating the real and imaginary parts of the complex analytic signal with a quadrature hybrid, determining the amplitude of the complex analytic signal by adding an even power-law transform of the real and imaginary parts of the complex analytic signal, and determining the phase of the complex analytic signal by comparing the real and imaginary parts of the complex analytic signal to zero and comparing an even power-law transform of the real and imaginary parts of the complex analytic signal to each other. Analog to digital converters and methods of converting complex analytic signals to digital signals are also disclosed.

Wideband polar receivers and method of operation are described. A phase-modulated input signal is received at a polar receiver that includes an injection-locked oscillator. The injection-locked oscillator includes a plurality of injection points. Based on the frequency of the input signal, a particular Nth harmonic is selected, and the input signal is injected at the set of injection points corresponding to the selected Nth harmonic. The injection-locked oscillator generates an oscillator output signal, and the phase of the input signal is determined from the phase of the oscillator output signal. In some embodiments, the oscillator output signal is frequency-multiplied by N, mixed with the input signal, and filtered for use in amplitude detection. The input signal is decoded based on the phase and amplitude information.

Techniques related to signal processing include setting up a first operation mode or a second operation mode. In the first operation mode: providing a first analogue signal to a first A/D converter by a first switch and a second analogue signal to a second A/D by second switch, and converting the first analogue signal to a first digital signal by the first A/D and the second analogue signal to a second digital signal by the second A/D. In the second operation mode: demodulating a third analogue signal to an in-phase signal and a quadrature signal by an I-Q-demodulator, providing the in-phase signal to the first A/D by the first switch, providing the quadrature signal to a second A/D by second switch, converting the in-phase signal to a third digital signal by the first A/D, and converting the quadrature signal to a fourth digital signal by the second A/D.

An IF filter band-limits an intermediate frequency signal outputted from a mixer. An AFC unit controls the oscillation frequency of a PLL so that the frequency of the intermediate frequency signal is a predetermined frequency. When the AFC unit controls the oscillation frequency of the PLL, a band control unit controls the passing characteristic of the IF filter to the passing characteristic of a wide band, and after the completion of the control, controls the passing characteristic of the IF filter to the passing characteristic of a narrow band. A frequency correction unit refers to a filter information storage unit, and corrects the oscillation frequency controlled by the AFC unit according to the difference between the center frequency of the passband of the passing characteristic of the wide band and the center frequency of the passband of the passing characteristic of the narrow band.

Wideband polar receivers and method of operation are described. A phase-modulated input signal is received at a polar receiver that includes an injection-locked oscillator. The injection-locked oscillator includes a plurality of injection points. Based on the frequency of the input signal, a particular Nth harmonic is selected, and the input signal is injected at the set of injection points corresponding to the selected Nth harmonic. The injection-locked oscillator generates an oscillator output signal, and the phase of the input signal is determined from the phase of the oscillator output signal. In some embodiments, the oscillator output signal is frequency-multiplied by N, mixed with the input signal, and filtered for use in amplitude detection. The input signal is decoded based on the phase and amplitude information.

Methods and systems for generating a digital representation of the amplitude and phase of a bandpass signal are disclosed. The methods comprise filtering the bandpass signal with a bandpass filter, generating the real and imaginary parts of the complex analytic signal with a quadrature hybrid, determining the amplitude of the complex analytic signal by adding an even power-law transform of the real and imaginary parts of the complex analytic signal, and determining the phase of the complex analytic signal by comparing the real and imaginary parts of the complex analytic signal to zero and comparing an even power-law transform of the real and imaginary parts of the complex analytic signal to each other. Analog to digital converters and methods of converting complex analytic signals to digital signals are also disclosed.

A radar system is disclosed for detecting profiles of objects, particularly in a vicinity of a machine work tool. The radar system uses a direct digital synthesiser to generate an intermediate frequency off-set frequency. It also uses an up-converter comprising a quadrature mixer, single-side mixer or complex mixer to add the off-set frequency to the transmitted frequency. It further uses a down-converter in the receive path driven by the off-set frequency as a local oscillator. The radar system enables received information to be transferred to the intermediate frequency. This in turn can be sampled synchronously in such a way as to provide a complex data stream carrying amplitude and phase information. The radar system is implementable with a single transmit channel and a single receive channel.

Methods and systems for generating a digital representation of the amplitude and phase of a bandpass signal are disclosed. The methods comprise filtering the bandpass signal with a bandpass filter, generating the real and imaginary parts of the complex analytic signal with a quadrature hybrid, determining the amplitude of the complex analytic signal by adding an even power-law transform of the real and imaginary parts of the complex analytic signal, and determining the phase of the complex analytic signal by comparing the real and imaginary parts of the complex analytic signal to zero and comparing an even power-law transform of the real and imaginary parts of the complex analytic signal to each other. Analog to digital converters and methods of converting complex analytic signals to digital signals are also disclosed.