Abstract:
Various techniques for biasing a radio frequency digital-to-analog converter are described. In one embodiment, a baseband processor (120) may comprise a plurality of output drivers (155, 156, 157-1 ...157-n) to generate a plurality of base currents for biasing a radio frequency digital-to-analog converter (110). The baseband processor (120) may comprise a serial control interface (131, 210) to generate a programming signal for controlling a relationship among the plurality of base currents.
Abstract:
A system, apparatus, method and article to emulate a filter using digital elements are described. The apparatus may include a digital-to-analog converter (110, 500) having an impulse response emulator (202, 510), the impulse response emulator (202, 510) to receive multiple digital signals each having a predetermined waveform, and convert a sequence of bits from each digital signal to a predetermined analog waveform corresponding to the sequence of bits. In preferred embodiments, the sequence of bits can be converted using a lookup table (506) or a digital filter (704).
Abstract:
A compact patch antenna (300) having a cavity (350) underneath a driver patch (310), so that the electromagnetic volume of the antenna is expanded without increasing the overall area of the antenna (300). The compact patch antenna (300) comprises a base layer (390) having the cavity (350), a ground plane (330) located on the base layer (390), and having an opening (340) over at least a portion of the cavity (350), a substrate (320) located on the ground plane (330), and the driver patch (310) located on the substrate (320). The invention further provides a method for constructing a compact patch antenna (300), comprising the steps of providing a base layer (390) having the cavity (350), providing a ground plane (330) located on the base layer (390), and having an opening (340) over at least a portion of the cavity (350), providing a substrate (320) located on the ground plane (330), and providing a driver patch (310) located on the substrate (320).
Abstract:
An apparatus (100) includes an antenna (102) (e.g., a monopole antenna), a first load (110), and a second load (112). The antenna (102), which extends substantially along an axis (103), has a first end (104) and a second end (106). The first load (110) is coupled to the antenna at the first end (104), while the second load (112) is coupled to the antenna (102) between the first end (104) and the second end (106). Both the first and second loads (110, 112) are symmetrical with reference to the axis. The apparatus is arranged to operate in at least two frequency bands, such as the Advanced Mobile Phone System (AMPS) band from about 824 MHz to about 894 MHz and the Personal Communications Service (PCS) band from about 1850 MHz to about 1990 MHz. The antenna (120) and first and second loads (110, 112) may be formed on the surface of a printed circuit board and may be symmetrically disposed relative to the axis (103)
Abstract:
The invention includes an apparatus and method for transmission power control in a wireless communication system. The method includes receiving at least one input parameter indicative of a transmission power level (302) for a wireless transmission, determining from said at least one input parameter whether the wireless transmission originates from a fast fading source or a slow fading source (304), and generating gain control settings to control the power supplied to the wireless terminal (318) based at least in part on said determination.. The apparatus for power control (10) in a wireless terminal includes a processor (14) for receiving at least one input parameter indicative of a transmission power level (32, 34, 36, 38, 40) and for generating a control parameter (42) based on the at least one input parameter (32, 34, 36, 38, 40), and a controller (16) for regulating an output transmission power level of the wireless terminal based on the control parameter
Abstract:
A process (100) of determining target parameters of an object within a field of detection of an automotive radar system, comprises the steps of (a) establishing a target range from a sequence of ranges (101); (b) dwelling on the target range for an initial dwell time to obtain sensor data (102); (c) determining if the sensor data corresponds to the presence of an object or to the absence of an object (103) at the target range based on probability density distributions of an object being present and being absent at the target range, and if such determination cannot be made, then repeating steps (b) - (c) until the determination can be made; (d) if the sensor data is determined to correspond to the presence of an object in step (c), then dwelling at the target range for an extended dwell time to obtain additional sensor data for determining the target parameters (104) of the object before proceeding to step (e); and (e) establishing the next of the sequence of ranges (105) as the target range before reiterating steps (b)-(e).
Abstract:
A system for optimally recharging a battery cell while powering a device connected to the battery pack, in which an electronic switch (22) connects a battery pack power-output either to the battery cells (12) or to a second power-input contact (20). When not recharging, the battery-pack power-output contact (16) is connected to the battery cells (12), thereby powering the device from the cells. When recharging via a charging unit, the battery pack's power-output terminal is uncoupled from the cells (12) and coupled to a power source of the charging unit, thereby powering the device from the charging unit. At the same time, a voltage is supplied to the battery cells (12), thereby recharging them. The switching may be activated by a voltage supplied by the charging unit to a temperature monitoring thermistor (24) in the battery pack. In this way, the battery pack's power output may be automatically switched whenever it is placed in the charging unit.
Abstract:
A receiver circuit including a differential amplifier (200, 300, 400) and at least one common mode feedback circuit (240) coupled to the differential amplifier (200, 300, 400) for providing a control current (I CMFB ) to the differential amplifier for (200, 300, 400) regulating a common mode voltage of the differential amplifier (200, 300, 400). The receiver circuit provides integration and sampling on an input signal, and may be used as a portion of a sensor circuit.
Abstract:
A circuit configuration for introducing bias in balanced lines capable of high frequency operation comprises top (30H) and bottom layers (30E) formed on a semiconductor substrate (30). The circuit includes two balanced metallized lines (33,32) positioned on the substrate (30). Each metallized line has a serpentine line (34,35,36,37) configuration connected thereto. The space between the lines is a virtual ground (31). The serpentine line configurations are congruent with elements on the substrate layers (30H,30E) to provide a completed circuit. The elements are coupled to a central metallic area (39), which in turn is coupled to a bias line (38) through an open-line stub (50), which extends beyond the virtual ground (31) and which provides equal capacitive coupling to the balanced lines (33,32). In this manner, the balanced line configuration includes capacitors and inductors which are symmetrically distributed and which provide resonance at the designed operating frequency. The bias line (38) thus formed is RF grounded due to the virtual ground (31) and is disconnected from the actual balanced lines (33,32).