Abstract: A demodulator for modulated RF signals comprises a passive four port structure (1). The four port structure (1) has a first input (3) for supplying a modulated RF signal to be demodulated. A second input (2) is supplied with a RF signal from a local oscillator (21). Two output terminals are connected to power sensors (4, 5). The RF signal from the local oscillator (21) is supplied to the second input (3) of the four port structure (1) without being RF switched by an RF switch. The demodulator is particularly useful for modulation schemes with a finite number of magnitude states (nQAM modulation).

Abstract: A three port structure for the down conversion demodulation of a digitally modulated RF signal is proposed, wherein no RF switches are provided. The three port structure (1) has a first input (2) for the RF signal to be down converted and a second input (3) for a RF signal originating from a local oscillator (8). An output (4) of the three port structure (1) is supplied to a power sensor unit (5). The RF signal from the local oscillator (8) is modulated (7) before it is supplied to the three port structure (1).

Abstract: A technique for calibrating a N-port receiver, such as for example a 5- or 6-port receiver is proposed. The N-port receiver (1) comprises a first input (2) for a RF signal to be detected, a second input (3) for a RF signal originating from a local oscillator (4) and N−2 output terminals. Calibrating signals are generated on the basis of the RF signal supplied by the local oscillator (4). The calibration signals are fed to the first input (2) and/or the second input (3) of the N-port receiver (1). Calibration coefficients are calculated on the basis of the output signals generated by the N-port receiver (1) in response to the feeding of the calibration signals. The calibration signals are unmodulated signals and are only processed by means of a passive RF circuitry in the calibration device (100). The solutions according to the present invention allow a simple calibration of N-port receivers, which can be used as IQ demodulators or converters.

Abstract: The present invention relates to a demodulation structure and method for downconverting and demodulating a digitally modulated signal So, with a local oscillator means (1; 5; 8) for providing a local oscillator signal Slo a mixer means (2) for mixing said local oscillator signal Slo and said digitally modulated signal S0 in order to obtain a mixed signal, a lowpass filter means (3) for lowpass filtering the mixed signal from the mixer means (2) and an analog-to-digital converting means (4) for converting the filtered signal from the lowpass filter means (3) into a downconverted and demodulated digital signal Sl, whereby the local oscillator signal is set in respect to the modulated digital signal so that the downconverted and demodulated digital signal output from the analog-to-digital converting means comprises to serially arranged information parts. The present demodulation structure provides a very simple structure with improved amplitude and phase imbalances.

Abstract: A RF receiver for modulated RF signals based on a N-port junction (1) providing LO/RF isolation is proposed. N thereby is an integer larger than two, such that the N-port junction (1) can be preferably a three port, four port, five port and six port junction. The N-port junction (1) supplied with a first RF signal at a first input (2) and with a second RF signal originating from a local oscillator (2) at a second input (3). An isolation block (13) comprising an active circuitry (22) is comprised in the N-port junction for isolating the second input (3) from the first input (1). Thereby can be ensured that the LO signals are significantly attenuated at the RF port (2).

Abstract: A radar sensor and a radar antenna are for monitoring the environment of a motor vehicle. A compact construction is achieved by the planar array of both the control circuit and the radar antenna, so that the radar sensor may be located, for example, in the area of a motor-vehicle bumper. Example configurations consist of the separate line support for arranging lines to transmit high-frequency signals between the control circuit and the radar antenna and the configuration of the radar antenna as a Rotman lens, in relation to the signal propagation times and the layered arrangement of Rotman lens and group antenna.

Abstract: The present invention relates to an antenna comprising a planar dielectric substrate (1) comprising a front (5) and a back dielectric face (6), at least one subantenna means comprising a first (2) and second (3) element for radiating and receiving circular polarized electromagnetic signals, at least one transmission line means (4) for transmitting signals from and to said at least one subantenna means, characterized in that the first (2) and second (3) elements of the subantenna means are slots (2, 3) of a spiral shape and are connected to each other to form a double spiral (9) slot with both spirals (2, 3) having the same sense of rotation, the subantenna means being arranged on the front dielectric face (5) of the substrate and the transmission line (4) means being arranged on the back dielectric faces (6) of the substrate (1).

Abstract: The present invention relates to a circular polarized antenna comprising a planar dielectric substrate comprising a front and a back dielectric face, at least one subantenna means comprising a first and second element for radiating and receiving circular polarized electromagnetic signals, at least one transmission line means for transmitting signals from and to said at least one subantenna means, wherein the antenna is characterized in that the first and second elements of the subantenna means are slots arranged orthogonal to each other in a V-shape on the front dielectric face of the substrate and in that the transmission line means are arranged on the back dielectric face of the substrate. This structure provides a simple configuration which can be produced at low costs and is suitable for the use in a planar array antenna, in particular due to the decoupling of the feed system from the radiating element.

Abstract: The present invention relates to an active reflector (10) for use in indoor wireless data communication systems comprising receiving means (11) for receiving signals from a first mobile terminal (13) and transmitting means (12) for transmitting the received signals to a second mobile terminal (14) in an omni-directional way, so that a direct communication with high data rates between mobile terminals in an indoor environment is enabled, whereby the active reflector is adapted to be mounted above the mobile terminals in the indoor environment to ensure essentially a line of sight connection between the active reflector and each mobile terminal. No cost-intensive baseband processing and/or broadband cabling infrastructure is necessary, so that a simple and cost-effective indoor communication is enabled.

Abstract: The present invention relates to a circular polarized antenna 0comprising a planar dielectric substrate (1) comprising a front (5) and a back (6) dielectric face, at least one subantenna means comprising a first (2) and second (3) element for radiating and receiving circular polarized electromagnetic signals, at least one transmission line means (4) for transmitting signals from and to said at least one subantenna means, wherein the antenna is characterized in that the first and second elements (2, 3) of the subantenna means are slots arranged orthogonal to each other in a V-shape on the front dielectric face (5) of the substrate (1) and in that the transmission line means (4) are arranged on the back dielectric face (6) of the substrate (1). This structure provides a simple configuration which can be produced at low costs and is suitable for the use in a planar array antenna, in particular due to the decoupling of the feed system from the radiating element.

Abstract: The present invention relates to an antenna comprising a planar dielectric substrate (1) comprising a front (5) and a back dielectric face (6), at least one subantenna means comprising a first (2) and second (3) element for radiating and receiving circular polarized electromagnetic signals, at least one transmission line means (4) for transmitting signals from and to said at least one subantenna means, characterized in that the first (2) and second (3) elements of the subantenna means are slots (2, 3) of a spiral shape and are connected to each other to form a double spiral (9) slot with both spirals (2, 3) having the same sense of rotation, the subantenna means being arranged on the front dielectric face (5) of the substrate and the transmission line (4) means being arranged on the back dielectric faces (6) of the substrate (1).

Abstract: The present invention relates to a demodulation structure and method for downconverting and demodulating a digitally modulated signal S0, with a local oscillator means (1; 5; 8) for providing a local oscillator signal Slo, a mixer means (2) for mixing said local oscillator signal Slo and said digitally modulated signal S0 in order to obtain a mixed signal, a lowpass filter means (3) for lowpass filtering the mixed signal from the mixer means (2) and an analog-to-digital converting means (4) for converting the filtered signal from the lowpass filter means (3) into a downconverted and demodulated digital signal S1, whereby the local oscillator signal is set in respect to the modulated digital signal so that the downconverted and demodulated digital signal output from the analog-to-digital converting means comprises two serially arranged information parts.