Abstract:
Example computer-implemented methods, computer-readable media, and computer systems are described for providing communication protocol architecture or framework for magnetic induction (MI)-based communications in wireless underground sensor networks (WUSNs), for example, in underground oil reservoirs. In some aspects, environment information of an underground region that affects the transmission qualities of MI communications is evaluated. A protocol stack is identified. The protocol stack includes a number of layers for MI communications among a number of sensors in a WUSN in the underground region. A cross-layer framework and the distributed protocol are built to jointly optimize communication functionalities of the plurality of layers based on the evaluation.
Abstract:
A spread-spectrum generator is provided. The spread-spectrum generator includes a delay module and a control module. The delay module is controlled by a first control signal to delay an input signal by a delay time, and thereby generate a delay signal. The control module is coupled to the delay module for detecting a first edge of the delay signal, and thereby generating the first control signal. Accordingly, the spread-spectrum generator can spread the frequency of the input signal by delaying the input signal by various delay time, and the spread-spectrum generator can also reduce electromagnetic interference (EMI).
Abstract:
The present invention relates to a dielectric composition which can be densified at a temperature no higher than 1000° C. and can provide ceramic products with a dielectric constant of 20 to 45 and a quality constant of 1000 to 1300 at 7 GHz. The dielectric composition comprises 20-90 vol % borosilicate glass and 10-80 vol % TiO2 ceramic. Multilayered microwave dielectric ceramic elements can be prepared by mixing the composition of the present invention with an organic solvent, a polymer binder and a plasticizer, forming a green sheet from the mixture by tape casting, screen-printing and laminating the green sheet, and then cofiring the multilayer ceramic laminate with a high electrical conductivity metal, such as Ag and Cu.
Abstract:
A receiver and a method for dynamically adjusting sensitivity of the receiver are provided. The receiver includes a detection unit and a receiving unit. The detection unit detects an input signal group, and outputs a detection result. The receiving unit receives the input signal group according to a sensitivity. Wherein, the receiving unit dynamically adjusts the sensitivity used for receiving the input signal group according to the detection result of the detection unit.
Abstract:
The clock signal detection circuit includes a lock detection circuit, a duty cycle detection circuit, a first logic circuit, and a counter. The lock detection circuit detects whether an input clock signal and a feedback clock signal of a delay locked loop are in phase. The duty cycle detection circuit detects whether the duty cycle of the input clock signal is within a percentage range. The first logic circuit, electrically connected to the lock detection circuit and the duty cycle detection circuit, outputs a detecting result signal which is at first logic level when the input clock signal are in phase with the feedback clock signal, and the duty cycle of the input clock signal is within a percentage range. The counter outputs a lock detection signal which is at the first logic level when the detecting result signal has maintained at the first logic level for a first constant period of time.
Abstract:
A low-fire, low-dielectric ceramic composition is disclosed. The ceramic composition comprises a mixture of finely divided particles consisting of 30-90% by volume of Ca—Ba—Al—Zn—Si glass and 70-10% by volume of oxides, which can be densified up to 95% at temperatures of 800-1000° C. The sintered body produced thereby exhibits a dielectric constant in the range of 6-10 and a dielectric loss in the range of 0.01%-0.5% at 1 MHz. The ceramic composition can be processed with organic solvent, polymeric binder and plasticizer to produce a green sheet which is co-firable with high electrical conductivity metal such as gold, silver, silver-palladium and copper.
Abstract:
A low-fire, low-dielectric ceramic composition is disclosed. The ceramic composition comprises a mixture of finely divided particles consisting of 30-90% by volume of Ca--Pb--Al--Zn--B--Si glass and 70-10% by volume of oxides, which can be densified up to 95% at temperatures of 800-1000.degree. C. The sintered body produced thereby exhibits a dielectric constant in the range of 6-10 and a dielectric loss in the range of 0.01%-0.5% at 1 MHz. The ceramic composition can be processed with organic solvents, polymeric binders and plasticizers to produce a green sheet which is co-firable with high electrical conductivity metals such as gold, silver, silver-palladium and copper.
Abstract:
A multi-phase clock generator including a first delay locked loop, a reference signal generator and a second delay locked loop is provided. The first delay locked loop generates 2N phase clock signals according to an input clock signal, so as to equally divide a clock period of the input clock signal into 2N predetermined phases, where N is a positive integer. The reference signal generator selects two phase clock signals according to a digital signal, and adjusts an output ratio of the two phase clock signals in 2M clock periods to serve as a reference clock signal. The second delay locked loop delays a first phase clock signal according to a phase difference between the reference clock signal and an output clock signal. In this way, each predetermined phase is further equally divided into 2M sub-phases, so that the multi-phase clock generator has 2(N+M) phase selections.
Abstract:
A multi-phase clock generator including a first delay locked loop, a reference signal generator and a second delay locked loop is provided. The first delay locked loop generates 2N phase clock signals according to an input clock signal, so as to equally divide a clock period of the input clock signal into 2N predetermined phases, where N is a positive integer. The reference signal generator selects two phase clock signals according to a digital signal, and adjusts an output ratio of the two phase clock signals in 2M clock periods to serve as a reference clock signal. The second delay locked loop delays a first phase clock signal according to a phase difference between the reference clock signal and an output clock signal. In this way, each predetermined phase is further equally divided into 2M sub-phases, so that the multi-phase clock generator has 2(N+M) phase selections.
Abstract:
A phase selector including a plurality of buffers, a multiplexer, a first inverter, and a selecting circuit is provided. Each of the buffers provides a clock signal, and the clock signals have different phases. The multiplexer selectively outputs one of the clock signals as a switch signal according to a first control signal, wherein the first control signal is first portion of bits of a selecting signal. The input terminal of the first inverter receives a second control signal, wherein the second control signal is second portion of bits of the selecting signal, and the output terminal of the first inverter outputs an inverted signal. The selecting circuit transmits the second control signal of the selecting signal or the inverted signal to the output terminal of the phase selector according to the logic state of the switch signal.