41 results about "Spurline" patented technology

In an exemplary embodiment, a spurline filter comprises a capacitive element connected to a spur and either a through-line of the spurline filter or ground. In another embodiment, multiple capacitive elements are connected to the spur. In an exemplary embodiment, the capacitively loaded spurline filter provides a band rejection frequency response similar to the band rejection frequency response of a similar spurline filter that does not comprise at least one capacitive element but the capacitively loaded spurline filter has half the layout area or less. In an exemplary embodiment, the spurline filter comprises capacitive elements, where the capacitive elements are configured to reduce the resonant frequency of the filter.

The invention discloses an arbitrary dual-frequency Wilkinson power divider based on a composite left-handed transmission line, which includes three ports, four right-handed transmission lines, two left-handed transmission lines and isolation resistors; the method includes obtaining the frequency ratio of working frequency points, establishing the phase shift value of the transmission line, Create a port transmission line, create a right-hand transmission line, create a left-hand transmission line, and create an isolation circuit. The ordinary arbitrary dual-frequency Wilkinson power splitter produced by the present invention, the compact arbitrary dual-frequency power splitter based on the composite left-handed transmission line and negative phase shift technology, and the compact arbitrary dual-frequency power splitter of the double-section impedance transformation technology can overcome the traditional power splitter which can only be odd The defect of sub-frequency multiplication work is that the length of the branch line can be shortened to less than λg / 4, which satisfies dual-frequency work and has a compact structure. The power divider of the invention is simple in design, and the required microwave plates and components are easy to obtain and easy to process. The power splitter proposed by the invention can well meet the performance requirements of the power splitter at two operating frequency points.

A microwave filter is provided that includes a transmission line having a signal input port and a signal output port, a stub connected to the transmission line between the input port and the output port, and a spurline embedded in the stub. The microwave filter is configured to substantially attenuate a frequency while substantially passing at least one predetermined odd harmonic of the frequency.

A bandpass filter passes a range of frequencies with low loss while suppressing frequencies above and below the passed range of frequencies. One or more spurlines is included into the existing structure of the bandpass filter so that a selected odd multiple of the passed frequency range is suppressed.

A bandpass filter passes a range of frequencies with low loss while suppressing frequencies above and below the passed range of frequencies. One or more spurlines is included into the existing structure of the bandpass filter so that a selected odd multiple of the passed frequency range is suppressed.

The invention discloses a double-dimension reconfigurable orthocoupler. The double-dimension reconfigurable orthocoupler comprises a dielectric plate, an improved branch coupler, a frequency modulation bias unit and a power-division-ratio adjusting bias unit, wherein the improved branch coupler adopts a matts structure and consists of a basic branch line coupler and crossed-shaped microstrip lines; the frequency modulation bias unit consists of four frequency modulation bias circuits; the power-division-ratio adjusting bias unit consists of two power-division-ratio adjusting bias circuits, wherein a first microwave signal is accessed to the input port of the basic branch line coupler; each frequency modulation bias circuit adjusts equivalent electrical lengths of series arms and parallel arms based on a first preset bias voltage and the first microwave signal; meanwhile, each frequency modulation bias circuit adjusts equivalent impendence of the parallel arms based on a second preset bias voltage and the first microwave signal; and the output port outputs a second microwave signal with a preset center frequency and preset power-division ratio. Based on the double-dimension reconfigurable orthocoupler, continuous adjustment of the center frequency and the power-division ratio is realized, and the purposes of reconfigurable center frequency and power-division ratio, signal quadrature output and easy processing are achieved.

A combined microwave sensor comprises metal ground at the bottom layer, dielectric at the middle layer, an input port, an output port I, a branched line coupler, a power divider, an open resonant ring, a microstrip line I and a microstrip line II, wherein the input port, the output port I, the branched line coupler, the power divider, the open resonant ring, the microstrip line I and the microstrip line II are arranged in the top layer. The input port and the output port I are connected with a vector network analyzer. The output side of the branched line coupler is provided with an isolated port and the output port I. The input end of the power divider is connected with the input port. The output port II and the output port III are connected with an annular directional coupler through a microstrip line. The open resonant ring is arranged between the power divider, the branched line coupler and the two microstrip lines. The combined microwave sensor has advantages of effectively eliminating background noise, realizing testing for weak background signals, and ensuring large offset of the sensor resonant frequency through small disturbance of the tested object. Therefore the combined microwave sensor provided by the invention has higher sensitivity and higher accuracy in dielectric constant measurement and can be used in high-sensitivity testing with small dielectric constant change.

A method and a system for reading radio frequency identification (RFID) tags are provided. The method includes the following steps. First, receive a tag signal from the RFID tag. Recover a data clock rate from the tag signal according to statistics of pulse lengths of the tag signal. Next, determine a frame synchronization point of a data frame following a preamble in the tag signal by a signal correlation between the preamble and a predetermined signal pattern according to the data clock rate. Finally, decode the data frame by using an adaptive Viterbi algorithm on an extended trellis diagram. The extended trellis diagram includes a plurality of nodes and a plurality of branches connecting the nodes. The nodes and the branches are arranged according to the modulation scheme of the data frame and possible variations of the data clock rate.

The invention discloses a UHF frequency band passive RFID high-separation dual-frequency transceiver separator, which includes a microstrip coupling line directional coupler, a transmitter port, a receiver port, a load port and an antenna port, and is characterized in that it also includes an absorption resistor, a micro One of the strip line segments, the second of the microstrip line segment, one of the open branch lines, the second of the open circuit branch lines, the third of the open circuit branch lines and the microstrip open line, one end of one of the microstrip line segments and one end of one of the open circuit branch lines Connected to the load port, the other end of one of the microstrip line segments is connected to one end of the open circuit branch line two and one end of the microstrip line segment two, the other end of the microstrip line segment two is connected to one end of the open circuit branch line three and the absorption resistor One end of the snubber resistor is connected to one end of the microstrip open line. The invention can simultaneously realize the high-separation separation of RFID transceiving signals on two frequency bands, and improve the working distance of the RFID reader-writer.