Abstract: A mobile device determines its location accurately by measuring the range to a position reflector as well as azimuth and elevation angles of arrival (AOA) at the reflector. The mobile can transmit a coded radar signal and process reflections to determine its location. The reflectors may include internal delays that can identify the reflector and provide transmit/receive separation for the mobile. The reflection can include a primary and further delayed secondary reflection. The mobile can determine the internal delay of the reflector based on the delay between primary and secondary reflections. The range and AOA information can be combined with information about the position, orientation, and characteristics of the reflectors to determine location. In some systems, the mobile device can determine its location in a three-dimensional space using reflections from only one reflector. The reflectors, which can be economically produced, can be unpowered and low profile for easy installation.

Abstract: A mobile device determines its location accurately by measuring the range to a position reflector as well as azimuth and elevation angles of arrival (AOA) at the reflector. The mobile can transmit a coded radar signal and process reflections to determine its location. The reflectors may include internal delays that can identify the reflector and provide transmit/receive separation for the mobile. The reflection can include a primary and further delayed secondary reflection. The mobile can determine the internal delay of the reflector based on the delay between primary and secondary reflections. The range and AOA information can be combined with information about the position, orientation, and characteristics of the reflectors to determine location. In some systems, the mobile device can determine its location in a three-dimensional space using reflections from only one reflector. The reflectors, which can be economically produced, can be unpowered and low profile for easy installation.

Abstract: An irrigation system continuously monitors status of lawns or plants under its care and directs water to where it is needed when it is needed to maintain lawn or plant health. The system can significantly reduce water usage, unnecessary seepage, and runoff. A irrigation robot refills a water tank from a refill station and then deliver the water where it is needed. An image sensor can continually take and analyze images of the lawns or plants to determine watering needs. The image sensor can also monitor the irrigation robot. The robot may also include a steerable water nozzle to deliver water to harder to reach locations.

Abstract: A mobile device determines its location accurately by measuring the range to a position reflector as well as azimuth and elevation angles of arrival (AOA) at the reflector. The mobile can transmit a coded radar signal and process reflections to determine its location. The reflectors may include internal delays that can identify the reflector and provide transmit/receive separation for the mobile. The reflection can include a primary and further delayed secondary reflection. The mobile can determine the internal delay of the reflector based on the delay between primary and secondary reflections. The range and AOA information can be combined with information about the position, orientation, and characteristics of the reflectors to determine location. In some systems, the mobile device can determine its location in a three-dimensional space using reflections from only one reflector. The reflectors, which can be economically produced, can be unpowered and low profile for easy installation.

Abstract: A mobile device determines its location accurately by measuring the range to a position reflector as well as azimuth and elevation angles of arrival (AOA) at the reflector. The mobile can transmit a coded radar signal and process reflections to determine its location. The reflectors may include internal delays that can identify the reflector and provide transmit/receive separation for the mobile. The reflection can include a primary and further delayed secondary reflection. The mobile can determine the internal delay of the reflector based on the delay between primary and secondary reflections. The range and AOA information can be combined with information about the position, orientation, and characteristics of the reflectors to determine location. In some systems, the mobile device can determine its location in a three-dimensional space using reflections from only one reflector. The reflectors, which can be economically produced, can be unpowered and low profile for easy installation.

Abstract: An irrigation system continuously monitors status of lawns or plants under its care and directs water to where it is needed when it is needed to maintain lawn or plant health. The system can significantly reduce water usage, unnecessary seepage, and runoff. A water nozzle with a pan and tilt capability can direct water where it is needed. An image sensor can continually take and analyze images of the lawns or plants to determine watering needs. The image sensor can also monitor where the water is landing while the irrigation system is delivering water to the lawns or plants. This information can be used to adjust the water delivery aim to ensure that the intended spots are accurately irrigated. A laminar flow nozzle with minimal flow dispersion can improve water deliver accuracy and detection of where the water lands.

Abstract: An irrigation system continuously monitors status of lawns or plants under its care and directs water to where it is needed when it is needed to maintain lawn or plant health. The system can significantly reduce water usage, unnecessary seepage, and runoff. A water nozzle with a pan and tilt capability can direct water where it is needed. An image sensor can continually take and analyze images of the lawns or plants to determine watering needs. The image sensor can also monitor where the water is landing while the irrigation system is delivering water to the lawns or plants. This information can be used to adjust the water delivery aim to ensure that the intended spots are accurately irrigated. A laminar flow nozzle with minimal flow dispersion can improve water deliver accuracy and detection of where the water lands.

Abstract: A method and system for disabling a mobile unit to handle a call processing function, after being away from its charging unit longer than a predetermined time period, allows a service provider to limit the mobility of the mobile unit with respect to its companion charging unit. Consequently, the service provider may limit the mobility of the mobile unit in a limited area, such as in a wireless local loop.

Abstract: Techniques to rotate the phase of a received signal to compensate for phase change or discontinuity introduced by circuit elements located directly in the receive signal path. One or more control signals are received, with each control signal being provided to adjust a particular characteristic of one or more circuit elements associated with the receive signal path. A phase rotation corresponding to an operating state defined by the control signals is then determined, and the phase of the received signal is rotated by an amount related to the determined phase rotation. In some designs, the phase rotation is performed on digitized inphase IIN and quadrature QIN samples to generate phase rotated IROT and QROT samples. The phase rotation can be performed by a complex multiply (after DC offset compensation) and, for ease of implementation, can be performed digitally in discrete increments (e.g., 90° increments).

Abstract: The frequency error of an oscillator is minimized by characterizing the oscillator. A reference signal from an external source containing a minimal frequency error is provided to an electronic device. The external signal is used as a reference frequency to estimate the frequency error of an internal frequency source. The electronic device monitors parameters that are determined to have an effect on the frequency accuracy of the internal frequency source. Temperature is one parameter known to have an effect on the frequency of the internal frequency source. The electronic device collects and stores the values of the parameters as well as the corresponding output frequency or frequency error of the internal frequency source. The resultant characterization of the internal frequency source is used to compensate the internal frequency source when the internal frequency source is not provided the external reference signal.

Abstract: A method and system for disabling a mobile unit to handle a call processing function, after being away from its charging unit longer than a predetermined time period, allows a service provider to limit the mobility of the mobile unit with respect to its companion charging unit. Consequently, the service provider may limit the mobility of the mobile unit in a limited area, such as in a wireless local loop.

Abstract: A method and system for disabling a mobile unit to handle a call processing function, after being away from its charging unit longer than a predetermined time period, allows a service provider to limit the mobility of the mobile unit with respect to its companion charging unit. Consequently, the service provider may limit the mobility of the mobile unit in a limited area, such as in a wireless local loop.

Abstract: The frequency error of an oscillator is minimized by characterizing the operating environment of the oscillator. An electronic device monitors parameters that are determined to have an effect on the frequency accuracy of the internal frequency source. Temperature is one parameter known to have an effect on the frequency of the internal frequency source and a primary contributor to device temperature is the RF Power Amplifier (PA). The electronic device collects and stores the activity level of the PA. The effective PA duty cycle over a predetermined period of time is calculated. The LO operating environment is stabilized by operating the PA at the calculated duty cycle when the LO is required to operate in a high stability mode.

Abstract: A programmable linear receiver which provides the requisite level of system performance at reduced power consumption. The receiver minimizes power consumption based on measurement of the non-linearity in the output signal from the receiver. The amount of non-linearity can be measured by the RSSI slope or energy-per-chip-to-noise-ratio (Ec/Io) measurement. The RSSI slope is the ratio of the change in the output signal plus intermodulation to the change in the input signal. The input signal level is periodically increased by a predetermined level and the output signal from the receiver is measured. The output signal comprises the desired signal and intermodulation products from non-linearity within the receiver. When the receiver is operating linearly, the output signal level increases dB per dB with the input signal level. However, as the receiver transitions into non-linear region, intermodulation products due to non-linearity increase faster than the desired signal.

Abstract: A method and system for disabling a mobile unit to handle a call processing function, after being away from its charging unit longer than a predetermined time period, allows a service provider to limit the mobility of the mobile unit with respect to its companion charging unit. Consequently, the service provider may limit the mobility of the mobile unit in a limited area, such as in a wireless local loop.

Abstract: A receiver that downconverts input signals modulated using first, second, third and fourth modulation formats to a common intermediate frequency range. The first and second modulation formats are transmitted to the receiver in a first frequency range, the third modulation format is transmitted to the receiver in a second frequency range, and the fourth modulation format is transmitted to the receiver in a third frequency range. The input signals are provided to first, second and third band selection filters that respectively select first, second and third frequency ranges. A first downconverter is coupled to an output of the first band selection filter, and downconverts signals from the first frequency range to the common intermediate frequency range.

Abstract: An inventive high-resolution Delta-Sigma analog-to-digital converter using a Continuous-Time implementation having suppressed sensitivity to clock jitter. The inventive method and apparatus suppresses the sensitivity to jitter by the square of the oversampling ratio when compared to current Continuous-Time implementations of Delta-Sigma modulators. The present invention eliminates the clock jitter disadvantage between sampled-data and Continuous-Time implementations of Delta-Sigma modulators. The present invention preferably includes a digital-to-analog converter that ensures that the integral of an output voltage is constant over a clock duty cycle regardless of clock jitter. The digital-to-analog converter preferably includes at least two switches and a capacitor. A first switch is used to charge the capacitor and a second switch is used to discharge the capacitor. Each switch is controlled by a clock phase wherein the sum of the two phases equals the clock duty cycle.

Abstract: A programmable dynamic range receiver which provides the requisite level of performance at reduced power consumption. The .SIGMA..DELTA. ADC within the receiver is designed with one or more loops. Each loop provides a predetermined dynamic range performance. The loops can be enabled or disabled based on the required dynamic range and a set of dynamic range thresholds. The .SIGMA..DELTA. ADC is also designed with adjustable bias current. The dynamic range of the .SIGMA..DELTA. ADC varies approximately proportional to the bias current. By adjusting the bias current, the required dynamic range can be provided by the .SIGMA..DELTA. ADC with minimal power consumption. A reference voltage of the .SIGMA..DELTA. ADC can be descreased when high dynamic range is not required, thereby allowing for less bias current in the .SIGMA..DELTA. ADC and supporting circuitry. The dynamic range of the .SIGMA..DELTA. ADC is a also function of the oversampling ratio which is proportional to the sampling frequency.

Abstract: A receiver comprising a sigma-delta analog-to-digital converter (.SIGMA..DELTA. ADC) can be utilized in one of four configurations, as a subsampling bandpass receiver, a subsampling baseband receiver, a Nyquist sampling bandpass receiver, or a Nyquist sampling baseband receiver. For subsampling .SIGMA..DELTA. receivers, the sampling frequency is less than twice the center frequency of the input signal into the .SIGMA..DELTA. ADC. For Nyquist sampling .SIGMA..DELTA. receivers, the sampling frequency is at least twice the highest frequency of the input signal into the .SIGMA..DELTA. ADC. For baseband .SIGMA..DELTA. receivers, the center frequency of the output signal from the .SIGMA..DELTA. ADC is approximately zero or DC. For bandpass .SIGMA..DELTA. receivers, the center frequency of the output signal from the .SIGMA..DELTA. ADC is greater than zero.

Abstract: A bandpass .SIGMA..DELTA. DC utilizing either a single-loop or a MASH architecture wherein the resonators are implemented as either a delay cell resonator, a delay cell based resonator, a Forward-Euler resonator, or a two-path interleaved resonator. The resonator can be synthesized with analog circuit techniques such as active-RC, gm-C, MOSFET-C, switched capacitor, or switched current. The switched capacitor or switched current circuits can be designed using single-sampling, double-sampling, or multi-sampling circuits. The non-stringent requirement of a .SIGMA..DELTA. ADC using switched capacitor circuits allows the ADC to be implemented in a CMOS process to minimize cost and reduce power consumption. Double-sampling circuits provide improved matching and improved tolerance to sampling clock jitter. In particular, a bandpass MASH 4-4 .SIGMA..DELTA. ADC provides a simulated signal-to-noise ratio of 85 dB at an oversampling ratio of 32 for a CDMA application. The bandpass .SIGMA..DELTA.