摘要:
Closed loop wireless communication of signals using an adaptive transmit antenna array (3), in which a plurality of copies of signals to be transmitted by the transmit antenna array (3) are produced with delays and weights ( w j n ) that are functions of the multi-path transmission channel characteristics (H) from the transmit antenna array (3) to a receive antenna array (4) of a receiver (2) and are combined before transmission by the transmit antenna array. The delays and weights ( w j n ) of the transmit copies for each transmit antenna element are functions of the respective multi-path transmission channel characteristics ( h l=1 n,m =1 ,..., h l=L n , m=M ) from that transmit antenna element to the receive antenna array (4) ssuch that the multi-path signal components propagated to each receiver element are received with distinguishable delays according to the propagation path. The receiver (2) combines the received signal components from each receive antenna element with delays and weights ( u ) that are respective functions of the multi-path transmission channels. Preferably, the receiver comprises a multi-finger RAKE receiver (6) that copies the received signals from the receive antenna array with delays and weights ( u ) that are respective functions of the multi-path transmission channels and combines the copied received signals.
摘要:
A solenoid driver (10) capable of detecting the operational status of a solenoid (12) including the position of an armature within a solenoid coil and an operational method. The solenoid driver (10) generates a first solenoid current within the solenoid (12) and measures a first decay time t1. The first solenoid current is insufficient to pull the armature into the coil of the solenoid (12). A comparator circuit (22) continuously monitors the solenoid current and initiates a timer within a counter circuit (34) to compute the first current decay time. A second solenoid current is generated within the solenoid (12) that is sufficient to pull the armature into the coil of the solenoid (12). The second solenoid current is turned off and a second decay time t2 is measured. The decay times are stored in storage registers (R1, R2) within a controller (36). The controller (36) compares the measured decay times with stored values and outputs the armature position information over a communications bus (34).
摘要:
A new class of organometallic complexes having the following general formula:
where:
M 2 is a divalent metal; and R 1 to R 8 represent substitution possibilities at each position and each represents hydrogen or hydrocarbon groups or functional groups, for use in electroluminescent (EL) devices and a method of preparation are disclosed. The organometallic complexes are prepared by mixing organic ligands with metal salts in the presence of a base and a layer is formed in an EL device by vacuum evaporation. The organometallic material in the EL device serves as either an electron transporting layer or a light emission layer, or both.
摘要:
This invention relates to novel type electrochemical devices such as capacitors or batteries, among other devices, which have high capacitance or power to volume or weight ratios, or which have other valuable characteristics, and which are characterized by the practical use of one or more phenomena, including pseudocapacitance, "kinetic reversibility" (passage of approximately equal and substantial charge or discharge currents at about the same rate), "coulombic reversibiiity" (passage of substantially equal numbers of coulombs in the charging and discharging of the device), distinguishable energy states of electrodeposited species on surfaces, creation of surface layers, electrochromic effects, negative differential resistance, and frequency multiplying effects which occur during, or as a result of, the formation or modification of an electrodeposited layer or layers on, or separation of charges in double layers in, one or more electrodes and/or as a result of the reaction(s) occurring between electrode and electrolyte.
摘要:
An accurate and fast copy current circuit arrangement (250) and method for high current ratio having a first branch for carrying a first current ( I load ) ; a second branch for carrying a second current (2 I fb ) ; and a twisted current mirror arrangement (282, 284, 286, 288) coupled between the first branch and the second branch, wherein the second current (2 I fb ) is a copy representative of the first current ( I load ). The twisted current mirror arrangement (282, 284, 286, 288) includes a first current mirror having a first bipolar transistor (282) and a second bipolar transistor (284) whose bases are coupled together; and a second current mirror having a first MOSFET transistor (286) connected in series with the first bipolar transistor (282) and a second MOSFET transistor (288) connected in series with the second bipolar transistor (284), the first and second MOSFET transistors having their gates coupled together. A start-up current source (299) applies a start-up current to the junction between the first bipolar transistor (282) and the first MOSFET transistor (286) and provides bias during circuit operation. This avoids a conventional error amplifier, uses no closed voltage loop, and no capacitor to stabilize the voltage loop, and provides a faster response time. This provides more accurate copy current for high current ratio, better linearity and zero input error voltage.
摘要:
An improved metal hydride hydrogen storage alloy electrode (20) for use in an electrochemical cell (10). The improved electrode (20) includes a hydrogen storage alloy material (22) having a layer of a passivation material (25) disposed thereon.
摘要:
A wide bandwidth frequency discriminator circuit (200) employs a wide bandwidth limiting amplifier (202) to amplify the IF signal portion a received RF signal. A delay circuit (204), such as a micro strip transmission line, provides a delayed representation of the amplified signal to a multiplier circuit (206). The multiplier (206) in turn provides a product signal which is the product of the amplified output signal and the delayed representation of the amplified output signal. As will be appreciated, said product signal will be proportional to the phase difference between the amplified output signal and the delayed representation of the amplified output signal. This discriminator (200) operates to form a detection system capable of discriminating between desired and undesired components of the received RF signal even when said desired and undesired components are nearly identical in amplitude. This is due in part to the enhanced frequency response provided by the discriminator (200).
摘要:
An efficient apparatus for performing frequency conversion from a final IF frequency to a baseband frequency is described. A counter (401) generates two logical signals G1 (402) and G2 (403) which are passed to an exclusive-OR gate (404) and a multiplexer (406). When a control signal (411) is deasserted, multiplexer (406) passes signal G1 to I1 and signal G2 to I2; when control signal (411) is asserted, multiplexer (406) passes binary signal G1 to I2 (410) and signal G2 to I1 (407). Similarly, multiplexer (405) swaps its input real and imaginary samples when the output of exclusive-OR gate (404) is asserted; otherwise, it performs no operation on its input samples. Signals I1 (407) and I2 (410) are used to control arithmetic inverters (408) and (409) respectively. When the controlling signal for either inverter is asserted, the inventer performs arithmetic inversion, otherwise it performs no operation.
摘要:
The present invention encompasses a method for providing the same ohmic material contact (120, 122, 124) to N-type and P-type regions (70, 80) of a III-V semiconductor device. Specifically, an N-type region (70) extending through a semiconductor structure is formed. Additionally, a P-type region (80) extending through the substrate is formed. The P-type region (80) may be heavily doped with P-type impurities (81). A first ohmic region (117) is formed, contacting the N-type region (70). The first ohmic region may comprise an ohmic material including metal and an N-type dopant. A second ohmic region (119) is formed, contacting the P-type region (80, 81). The second ohmic region comprises the same ohmic material as the first ohmic region. One ohmic material that may be used is nickel-germanium-tungsten.