摘要:
A method for adjusting the transmitter power of a subscriber unit includes the steps of determining noise characteristic of a receiver site, measuring strength of a signal received from the subscriber, determining a power adjust value based on the noise characteristic and the received signal strength. The transmit power of the subscriber unit is adjusted according to the power adjust value.
摘要:
Improvement of quantization errors that arise in a delay line with finite resolution. A direct digital synthesizer (DDS), which contains a numerically controlled oscillator (NCO) and a digital-to-phase converter (DPC), is placed in the feedback loop of a phase locked loop (PLL). The DDS is used as a fractional divider of the voltage controlled oscillator (VCO) frequency, such that the reference frequency of the DDS is made variable. Alignment of the edges provided by the DDS delay line may then be adjusted. Mismatch errors in the DDS delay line are reduced by utilizing independently tunable delay elements.
摘要:
A signal generator consistent with certain embodiments of the invention has a reference clock (34) producing a periodic sequence of reference clock output pulses. A window generator (38) generates a plurality of time windows through which a selected plurality of the reference clock output pulses are selectively passed as windowed pulses so that the windowed pulses form a selected pattern of pulses. A programmable delay (46) has resolution of delay that has finer time granularity in delay than the period of the clock output pulses. The programmable delay (46) delays each of the windowed pulses by a programmed delay time to thereby provide a timing correction to the windowed pulses to produce an output pattern of pulses.
摘要:
A dynamically matched mixer system (200) for use in a direct conversion radio frequency (RF) receiver includes a frequency generator (201, 203, 205) that includes plurality of dividers (407) for providing differential local oscillator reference sources (FLO+ and FLO−) and mitigation frequency reference sources (F1 and F2) from reference oscillator (205). A mixer (209) mixes the differential local oscillator reference sources (FLO+ and FLO−) and the mitigation frequency reference sources (F1 and F2) while dynamic matching units (211, 213) are used for receiving the mitigation frequency reference sources and matching switching parameters of differential input signals (IRF+ and IRF−) and differential baseband output signals (IBB+ and IBB−). The frequencies of the mitigation frequency reference sources (F1 and F2) are selected so as to establish a non-integer relationship to the reference oscillator (201) for mitigating the occurrence of interference with FLO+ and FLO−.
摘要翻译:用于直接转换射频(RF)接收机的动态匹配混频器系统(200)包括频率发生器(201,203,205),其包括多个分频器(407),用于提供差分本地振荡器参考源(F and and> LO LO LO LO LO LO LO LO)和缓解频率参考源(F 1和F 2) 单元(211,213)用于接收缓解频率参考源和差分输入信号(I + RF +和I + RF - )的匹配切换参数和差分基带输出信号 (I BB +和/或BB - )。 选择缓解频率参考源(F 1和F 2)的频率以便建立与参考振荡器(201)的非整数关系,以便减轻与F LO和/ F SUB>。
摘要:
A digital frequency synthesizer includes one or more reference clocks (104, 1316, 1502A, 1504A, 1506A) optionally coupled through one or more pulse width reducers (106) to one or more main delay lines (108, 702, 1502B, 1504B, 1506B) that include a plurality of output taps (108B-108I, 702B-702E). During at least certain periods of the reference clock (104) a plurality of the output taps are coupled to a common output (130, 1312, 1508), thereby producing an output signal that has a frequency that exceeds a frequency of the one or more reference clocks. The coupling is preferably accomplished by transmission gates (114, 128, 720-724, 1420-1434) that are switched by gating pulses that are received from decoders (148, 150, 1418) via gating signal delay lines (134-146, 704-718, 1404-1416).
摘要:
An interference-robust coded-modulation scheme for optical communications and a method for modulating illumination for optical communications include optical signal transmitters connected to signal multipliers. The signal to be transmitted is multiplied by a pseudo-random noise code and transmitted within the transmitter emissions. A receiver converts the received modulated light and correlates the received signal. An estimate of the signal to be transmitted is made by multiplying the received signal by the noise code and correlating such multiplication over the length of the code. A threshold switch outputs the correlation result to a bit estimator approximately when a deterministic peak of the output signal exceeds a threshold.
摘要:
A parameter extraction technique for an electrical structure is based on a definition of network parameters that isolates pure mode responses of the electrical structure, and that makes mode conversion responses of the electrical structure negligible. A set of network parameters is obtained that represents pure mode responses for the electrical structure (410). These network parameters are processed to obtain model parameters that characterize each pure mode response (422, 424, 426, 428, 432, 434, 436, 438). Preferably, the mode specific parameters to combined to obtain mode independent parameters, such as coupling factor, propagation constant, and characteristic impedance values (440, 450).
摘要:
To reduce crosstalk in reentrant off-chip RF selectivity, differential circuits (402, 415), transmission lines (423, 424), and off-chip filters (422) are used in a structure that balances the parasitic capacitances associated with all of the differential elements. The structure includes a substrate (409) with a differential generating circuit (402) and a receiving circuit (415). Two differential transmission lines (423, 424), each with constant characteristic impedance, and each with balanced capacitance to ground, both being closely spaced for some distance, couple the circuits (402, 415) to closely spaced terminating pads (403). A ground plane (412) is shared under both transmission lines (423, 424). A second substrate (408) having a reentrant RF path (406) with the first substrate (409) contains an RF function such as a filter or a delay line.
摘要:
A high efficiency amplitude/phase modulation amplifier circuit (100) includes a first (102) and a second (106) high efficiency amplifier. These amplifiers (102 and 106) amplify two constant amplitude/phase modulated signals. A combiner (104) combines the output signals from the amplifiers (102) and (106) to produce a combined signal to a load (108). Two shunt elements (202 and 204) are included to prevent the reactive components of the combined signal from reaching the amplifiers (102) and (106). With no reactive components reflected back, the amplifiers (102 and 106) can remain non-linear even though they are used to amplify an amplitude/phase modulated signal which includes Amplitude Modulation (AM) components.
摘要:
An integrated-distributed-inductive-capacitive network (100) having a high dielectric electronically-tunable semiconductor integrated capacitor. The network (100) also includes a conductive layer (126) formed on the high dielectric semiconductor integrated capacitor, to provide the distributed resistance of the network (100). External contact to the network (100) is provided via a plurality of contact terminals (122A and 122B) which are coupled to the conductive layer (126).