摘要:
A radio transmission system is disclosed for operating in a multipath transmission environment having improved reception, and in the case of bi-directional systems, also improved transmission. This is achieved by using at least two reception beams, corresponding to one fixed reception beam and one scanning reception beam, and by continuously evaluating the quality of these beams as to their signal-to-noise-and-interference ratios or bit-error-rates (BERs). The best beam is dynamically chosen to be the fixed beam. Alternatively, the fixed beam is updated with the best beam acquired by the scanning beam as compared to the current fixed beam. In a bi-directional system, the receiving radio apparatus applies the direction of the best reception beam for transmission to the opposite radio apparatus.
摘要:
A method of electronic ballast protection including providing an electronic ballast having an AC/DC converter 104 with an electronic ballast input and a mains voltage connection 103 connectable to a mains voltage 102, an inverter 120 operably connected to the AC/DC converter 104 and having an electronic ballast output 125 connectable to a lamp 124, a control circuit 116 controlling the inverter 120, and a low voltage power supply 114 providing low voltage power to the control circuit 116; supplying power to the low voltage power supply 114 from the electronic ballast input when the mains voltage connection 103 is wired to mains voltage 102; and disconnecting the power to the low voltage power supply 114 when the electronic ballast output 125 is wired to the mains voltage 102.
摘要:
A method of electronic ballast protection including providing an electronic ballast having an AC/DC converter 104 with an electronic ballast input and a mains voltage connection 103 connectable to a mains voltage 102, an inverter 120 operably connected to the AC/DC converter 104 and having an electronic ballast output 125 connectable to a lamp 124, a control circuit 116 controlling the inverter 120, and a low voltage power supply 114 providing low voltage power to the control circuit 116; supplying power to the low voltage power supply 114 from the electronic ballast input when the mains voltage connection 103 is wired to mains voltage 102; and disconnecting the power to the low voltage power supply 114 when the electronic ballast output 125 is wired to the mains voltage 102.
摘要:
A driver for HID lamps comprises four switches and generates a constant DC current that is commutated at a low frequency. The driver comprises a filter capacitor. The occurrence of peak currents due to the charging or discharging of the filter capacitor is prevented by driving one of the switches at a high frequency immediately after commutation.
摘要:
The invention relates to an antenna diversity comprising a first and a second antenna element where the first antenna element is operated in an active mode whereas the second antenna element is operated in a parasitic mode. The present invention minimizes the amount of mismatch while still being able to maximize a predetermined signal quality criterion for the electromagnetic signal on the active path between the first antenna element and the transceiver. By providing a pre-selection unit 130 as well as a selection unit 140 for selecting an optimal adjustable impedance connected to the second antenna ensuring that the amount of said mismatch is below a predetermined threshold value and that simultaneously a predetermined quality criterion for the transceived electromagnetic signal is fulfilled best within the range determined by the allowable mismatch. The invention further relates to a method for operating such an antenna diversity.
摘要:
The invention relates to an antenna diversity comprising a first and a second antenna element one of which is operated in an active mode whereas the other one of which is operated in a parasitic mode. It is the object of the present invention to further minimize the amount of mismatch by still being able to maximize a predetermined signal quality criterion for the electromagnetic signal on the active path between the active antenna and the transceiver. This object is solved by a switching unit 120 for either operating the first antenna element in the parasitic mode and simultaneously operating the second antenna element in the active mode or vice versa and by providing a pre-selection unit 130 as well as a selection unit 140 for selecting an optimal configuration for the antenna diversity ensuring that the amount of said mismatch is below a predetermined threshold value and that simultaneously a predetermined quality criterion for the transceived electromagnetic signal is fulfilled best. The antenna diversity further comprises a control unit 150 for adjusting said selected configuration. The invention further relates to a method for operating such an antenna diversity.
摘要:
A driver for HID lamps includes four switches and generates a constant DC-current that is commutated at a low frequency. The driver includes a filter capacitor. The occurrence of peak currents due to the charging or discharging of the filter capacitor is prevented by driving one of the switches at a high frequency immediately after commutation.
摘要:
A waveguide comprises a longitudinal first conductor (110) located in an inner space of a box-shaped longitudinal shield conductor which is provided with a slot (122) defining a sliding support for a substantially plate-shaped coupler (300). The shield conductor (120) is provided with flanges (125, 126) extending substantially parallel to each other on opposite sides of the slot (122). A coupling conductor portion (322) faces the first conductor (110).
摘要:
In an electronic circuit for forming an antenna pattern, the antenna signals having the required phase shift are generated by means of two phase-locked loops which have a common reference signal. A control current, which is added at the output node of the charge pump 26 and/or 27, is used to control the phase shift of the antenna signals. This allows the implementation of the phase shift operation in the analog domain, which decreases the cost of a corresponding consumer device, such as a car-radio or a mobile communication system.
摘要:
A method of manufacturing a hybrid integrated circuit comprising a semiconductor element (1) and a piezoelectric filter (2), which are situated next to each other and connected to a carrier substrate (3). The semiconductor element comprises semiconductor regions (5, 6) which are formed in a silicon layer (13, 28); the piezoelectric filter comprises an acoustic resonator (8, 9, 10) which is situated on an acoustic reflector layer (7), which acoustic resonator comprises a layer of piezoelectric material (8), a first electrode (9) situated between the layer of piezoelectric material and the acoustic reflector layer, and a second electrode (10) which is situated on the opposite side of the piezoelectric layer and faces the first electrode. In the method, the semiconductor element is formed on the first side (11) of a silicon wafer (12, 25). On the same side of this wafer, also the layer of piezoelectric material and the first electrode are formed, after which the surface is covered with the acoustic reflector layer. Subsequently, an adhesive layer (22) is used to attach the structure thus formed with the acoustic reflector layer to the carrier substrate. Finally, at the location of the filter, silicon is removed from the second side of the wafer, and the comparatively thick acoustic reflector need not be patterned so that underlying features cannot be damaged during etching said reflector layer.