Abstract: A transceiver includes a local oscillation module, a transmitter section, and a receiver section. The local oscillation module is operable to generate a transmit local oscillation and a receive oscillation. The transmitter section includes a transmit mixing module and a transmit weaved connection that is operable to high frequency filter the transmit location oscillation. The transmit mixing module mixes the filtered transmit location oscillation with a transmit signal to produce an up-converted signal. The receiver section includes a receive mixing module and a receive weaved connection that is operable to high frequency filter the receive location oscillation. The receive mixing module mixes the filtered receive location oscillation with an RF received signal to produce a down-converted signal.

Abstract: A method and device for a compact microstrip bandpass filter that includes an input terminal, an output terminal, a plurality of quarter-wavelength resonators, a resonant disk, a plurality of layers, and a microstrip line which connects the resonant disk to a joint point of the quarter-wavelength resonators. A method of forming two signal paths in a compact microstrip bandpass filter includes forming a first signal path between an input terminal and an output terminal of the filter with a plurality of quarter-wavelength resonators with a resonant disk and a microstrip line which connects the resonant disk to a joint point of the quarter-wavelength resonators. The method includes forming a second signal path of the quarter-wavelength resonators, the filter includes a plurality of layers.

Abstract: Metallization layer structures for reduced changes in radio frequency characteristics due to registration error and associated methods are provided herein. An example resonator includes a first conductive layer defining an error limiting feature and a second conductive layer. The resonator further includes at least one communication feature configured to electrically couple the first conductive layer and the second conductive layer at a communication position. The error limiting feature is configured to reduce changes in radio frequency characteristics of the resonator due to registration error. Methods of manufacturing resonators are also provided herein.

Abstract: A resonant element is provided with a multilayer board, comprising a plurality of conductor layers isolated by a dielectric, a signal via conductor, penetrating through the multilayer board, and a plurality of ground vias, penetrating thought the multilayer board and disposed around the signal via conductor. The multilayer board comprises a first conductor layer, a second conductor layer, and a corrugated conductor layer disposed between the first and the second conductor layers. The corrugated conductor layer comprises a corrugated signal plate, connected to the signal via conductor, and a corrugated ground plate, connected to the plurality of ground vias, isolated from the corrugated signal plate by the dielectric.

Abstract: A circuit substrate has three wiring layers, wherein a signal line is formed in a first wiring layer; a ground plane is formed in a second wiring layer; a resonant line is formed in a third wiring layer. A circumferential slit is formed in the ground plane, wherein an island electrode separated from the ground plane is formed inside the slit. The left end of the resonant line is connected to the island electrode through an interlayer-connecting via, while the right end of the resonant line is connected to the ground plane through an interlayer-connecting via. A transmission line (or a microstrip line) is formed using the signal line and the ground plane, and therefore a complex resonator is formed to embrace the transmission line. This achieves band elimination with regard to a signal component of a resonance frequency among signals propagating through the microstrip line.

Abstract: Tunable radio frequency (RF) devices, such as phase shifters and filters, are formed by depositing thin film layers on a substrate and patterning the thin film layers by various lithography techniques. A thin film metal layer is patterned to form a plurality of capacitors and inductors, leaving at least two grounding regions that lie closely adjacent the capacitors and inductors. As patterned portions of the grounding regions are electrically isolated from each other. Performance of the devices are improved by electrically bridging the differential potential grounding regions.

Abstract: A filter of the present invention comprises a multilayer substrate, two terminals, a ground conductor and a hybrid resonator. The multilayer substrate includes a plurality of conductor layers and a dielectric configured to isolate said plurality of conductor layers from each other. The hybrid resonator is disposed in the multilayer substrate and comprises a first and a second resonant elements and a coupling strip connecting the first and said second resonant elements. Each resonant element comprises a signal via, a group of ground vias and an artificial dielectric. Each signal via is disposed through the multilayer substrate. Each group of ground vias is disposed through the multilayer substrate and configured to surround the signal via. Each artificial dielectric is disposed in the multilayer substrate and between the signal via and the group of ground vias.

Abstract: A micro-electro-mechanical transducer (such as a cMUT) having a non-flat surface is disclosed. The non-flat surface may include a variable curve or slope in an area where a spring layer contacts a support, thus making a variable spring model as the spring layer vibrates. The non-flat surface may be that of a non-flat electrode optimized to compensate the dynamic deformation of the other electrode during operation and thus enhance the uniformity of the dynamic electrode gap during operation. Methods for fabricating the micro-electro-mechanical transducer are also disclosed. The methods may be used in both conventional membrane-based cMUTs and cMUTs having embedded springs transporting a rigid top plate.

Abstract: A band-pass filter has a plurality of frequency band channels each including a first inductor having a first terminal coupled to a first balanced port and a second terminal coupled to a second balanced port. A first capacitor is coupled between the first and second terminals of the first inductor. A second inductor has a first terminal coupled to a first unbalanced port and a second terminal coupled to a second unbalanced port. The second inductor is disposed within a first distance of the first inductor to induce magnetic coupling. A second capacitor is coupled between the first and second terminals of the second inductor. A third inductor is disposed within a second distance of the first inductor and within a third distance of the second inductor to induce magnetic coupling. A second capacitor is coupled between first and second terminals of the third inductor.

Abstract: A filter is provided with a planar transmission line and a combined via structure connected to (both) one ends of the planar transmission line. The planar transmission line and the combined via structure are disposed in a same multilayer board. The combined via structure comprises two working parts. The first working part comprises a segment of signal via and a plurality of segments of ground vias surrounding the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias, smooth conductive plate and corrugated conductive plate. The smooth conductive plate and the corrugated conductive plate are connected to the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias and corrugated conductive plate. The corrugated conductive plate is connected to the signal via.

Abstract: Provided is a printed circuit board configured to remove undesired signals generated in a transmission line, the signals having frequencies that are integral multiples of a basic frequency. Two ¼ wavelength lines 5 and 6 each having a length that is ¼ of a basic frequency corresponding to a data rate of coded digital signal are arranged at a signal wiring layer, which is one of surface layers of a substrate 8, along a transmission line 3 for transmitting the digital signal. One end 15a of the first ¼ wavelength line 5 is opened, and another end 15b is grounded to a ground 7. Both ends 16a and 16b of the second ¼ wavelength line 6 are opened.

Abstract: An multi-band pass filter is disclosed. The multi-band pass filter in accordance with an embodiment of the present invention includes: a housing comprised with an input terminal and an output terminal separated from each other; a high pass filter installed in one inside of the housing and electrically connected to the input terminal and configured to form a plurality of resonator patterns with the circuit patterns on the printed circuit board; and a dual band reject filter series-connected with the high pass filter and provided between the high pass filter and the output terminal by forming a plurality of cavities inside the housing and furnishing each of the cavities with a resonator.

Abstract: A structural body includes: a first conductor and a second conductor of which at least portions are opposite to each other; a third conductor, interposed between the first conductor and the second conductor, of which at least a portion is opposite to the first conductor and the second conductor, and has a first opening; an interconnect provided in the inside of the first opening; and a conductor via which is electrically connected to the first conductor and the second conductor and is electrically insulated from the third conductor, wherein the interconnect is opposite to the first conductor and the second conductor, one end thereof being electrically connected to the third conductor at an edge of the first opening and an other end thereof being formed as an open end.

Abstract: In a high frequency filter, a multilayer structure includes a plurality of insulator layers, a first transmission line transmits an input signal, and a second transmission line is electromagnetic coupled with the first transmission line on the same insulator layer and transmits an output signal. A conductor layer defines capacitors with the first transmission line and the second transmission line with the insulator layer in between. A dielectric constant of the insulator layer that comes in contact with the first transmission line and the second transmission line is higher than a dielectric constant of an insulator layer other than the insulator layer.

Abstract: A resonance element according to an embodiment transmits a radio-frequency signal, and includes a first substrate, a second substrate, a first circuit element formed on the first substrate, a second circuit element formed on the second substrate, and a transmission line connecting the first circuit element and the second circuit element, and a peak of even mode resonance in which the first circuit element and the second circuit element resonate in the same phase is within a bandwidth of a transmission signal, and a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase is outside the bandwidth.

Abstract: A cavity filter having a piezoelectric tuning element is tuned by determining a desired oscillating frequency for the piezoelectric tuning element and applying that frequency through a phase-locked loop. The phase-locked loop maintains the piezoelectric tuning element at the desired frequency.

Abstract: A high-frequency signal line includes a base layer including first and second principal surfaces, a signal line provided on the first principal surface, a ground conductor provided on the first principal surface along the signal line, and a plurality of high-permittivity portions arranged along the signal line and in contact with a portion of both the signal line and the ground conductor, each of the high-permittivity portions having a higher specific permittivity than the base layer.

Abstract: A bandpass filter includes a first uniform impedance resonator comprising a first microstrip line and a second microstrip line, a second uniform impedance resonator which is axisymmetric to the first uniform impedance resonators, a first asymmetric stepped-impedance resonator comprising a third microstrip line and a fourth microstrip line, a second asymmetric stepped-impedance resonator which is axisymmetric to the first asymmetric stepped-impedance resonator, a third asymmetric stepped-impedance resonator consisting of a fifth microstrip line and a sixth microstrip line, a fourth asymmetric stepped-impedance resonator which is axisymmetric to the third asymmetric stepped-impedance resonator, a input consisting of a seventh microstrip line and connecting with the first microstrip line, and a output which is axisymmetric to the input and connects with the second uniform impedance resonator.

Abstract: A microstrip line filter comprising a coupling mechanism arranged to couple a first resonator and a second resonator, wherein the coupling mechanism includes a shared metallic coupling member arranged to have a predetermined dimension associated with an operation characteristics of the first and second resonators.

Abstract: A filter of an embodiment includes: a microstrip-line planar filter that includes an input line, resonators, and an output line, and has a passband with a center frequency f0; a metal case housing the planar filter; and structural components that include dielectric components, the structural components arranged in the metal case at an interval in the traveling direction of electromagnetic waves from the input line to the output line or in a direction perpendicular to the wavefront of the standing waves generated by the electromagnetic waves resonating in the metal case, the interval being ? to ½ wavelength in terms of the electrical length of the center frequency f0.

Abstract: A filter includes: an input terminal to which a fundamental wave signal and a harmonic signal group of the fundamental wave signal are supplied; an output terminal configured to output the fundamental wave signal supplied to the input terminal; a transmission line configured to connect the input terminal and the output terminal; an open-end stub configured to be provided corresponding to an odd harmonic signal among the harmonic signal group, coupled to the transmission line, and has a length corresponding to one quarter of a wavelength of the corresponding odd harmonic signal; a first short-end stub configured to be coupled to the transmission line and has a length corresponding to one quarter of a wavelength of the fundamental wave signal; and a second short-end stub configured to be coupled to the transmission line.

Abstract: Metallization layer structures for reduced changes in radio frequency characteristics due to registration error and associated methods are provided herein. An example resonator includes a first conductive layer defining an error limiting feature and a second conductive layer. The resonator further includes at least one communication feature configured to electrically couple the first conductive layer and the second conductive layer at a communication position. The error limiting feature is configured to reduce changes in radio frequency characteristics of the resonator due to registration error. Methods of manufacturing resonators are also provided herein.

Abstract: To sufficiently attenuate a common mode signal by passing an ultra-high speed differential signal through an ultra-high speed differential transmission line. A common mode filter comprises: a pair of conductive lines formed on a first dielectric layer to transmit a differential signal; a plurality of first divided floating grounds in a state of being separated from an external ground potential, and facing the conductive lines, with the first dielectric layer interposed between them, and formed by being divided into a plurality of numbers in a length direction of the conductive lines, and forming a distribution constant type differential transmission line for the differential signal, together with the conductive lines; and a first passive two-terminal network connected between the first divided floating grounds located at least at an input side or an output side of the first divided floating grounds, and the external ground potential.

Abstract: A laminated electronic device comprises two or more wiring layers including a first wiring layer and a second wiring layer, an insulating layer interposed between the first wiring layer and second wiring layer, and a through conductor extending through the insulating layer for electrically connecting a first conductor disposed on the first wiring layer to a second conductor disposed on the second wiring layer. The through conductor includes divergent sections at both ends, which have a diameter gradually increased toward the first conductor or second conductor.

Abstract: A narrowband filter tuned at a center frequency. The filter comprises an input terminal, an output terminal, and a plurality of resonators coupled in cascade between the input terminal and the output terminal. Each of the resonators is tuned at a resonant frequency substantially equal to the center frequency. The resonant frequencies of a primary set of the resonators and a secondary set of the resonators are of different orders.

Abstract: Several implementations disclosed herein are directed to compact-size common-mode filters that are suitable for implementation in densely populated multilayered printed circuit boards (PCBs) with numerous I/O ports—as well as integrated circuit (IC) chips and I/O connectors—to suppress EMI emissions. Certain implementation are specifically directed to filters for four differential signal lines that carry 10-Gb/s digital signals. These implementations provide common-mode suppression within gigahertz frequencies where common-mode noise comprising 10-Gb/s signal is problematic, but without any significant degradation of differential-mode signals. Moreover, certain of these implementations are directed to compact-size filters that suppress common-mode signal noise at 10.3 GHz associated with the fundamental harmonic 10 Gb/s-signals of XFI and SFI. In other implementations, a combination of filters is presented to provide common-mode noise suppression at both the first harmonic frequency of 10.

Abstract: An apparatus includes a filter that includes a multi-layer planar structure having a first layer and a second layer. The first layer includes an electronic band-gap structure that is configured to suppress a first frequency component of signals passing through the filter. The second layer includes a quarter-wavelength stub that is configured to suppress a second frequency component of the signals passing through the filter.

Abstract: A signal transmission device includes substrates and resonance sections resonating at the predetermined resonance frequency. At least one of the substrates is formed with two or more resonators in the second direction, and the remaining one or two or more of the substrates are each formed with one or more resonators in the second direction, and at least one of the resonance sections is configured by a plurality of resonators opposing one another in the first direction between the substrates, the opposing resonators form a coupled resonator resonating as a whole at the predetermined resonance frequency through electromagnetic coupling in a hybrid resonance mode, and in a state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis.

Abstract: Among other things, a circuit includes a first and a second electromagnetic resonator, each configured to operate in a transverse electromagnetic mode, and a coupling device configured to operate in the transverse electromagnetic mode, wherein the coupling device is connected to the first and second electromagnetic resonators and inductively couples the first and second electromagnetic resonators.

Abstract: A filter according to embodiments includes n resonators, an input line, and an output line. Each of the resonators includes a first comb-like structure, a second comb-like structure, and a connection line that connect the first and the second comb-like structure. The first and second comb-like structures have a plurality of first lines and a second line that is connected to one end of the first lines. The first lines of the first and the second comb-like structures are arranged parallel to each other. The connection line has bending portions. Further, a second comb-like structure of a k-th resonator and a first comb-like structure of a (k+1)-th resonator are arranged so as to have an interlaced arrangement, and a second comb-like structure of the (k+1)-th resonator and a first comb-like structure of a (k+2)-th resonator are arranged so as to have an interlaced arrangement.

Abstract: [Object] An object is to provide a bandpass filter that can be used for a wide frequency band and has a large degree of freedom in designing a passband, and a wireless communication module and a wireless communication device that use the bandpass filter. [Solution] A bandpass filter includes first to third resonance electrodes 31a, 31b, and 31c sequentially arranged side-by-side such that they are electromagnetically coupled to each other, the first to third resonance electrodes 31a, 31b, and 31c being grounded at one end and constituting first to third resonators, respectively; a first input/output coupling electrode 40a facing the first resonance electrode 31a and electromagnetically coupled thereto; a second input/output coupling electrode 40b facing the second resonance electrode 31b and electromagnetically coupled thereto; and a resonator coupling electrode 43 configured to provide electromagnetic coupling between the first resonance electrode 31a and the third resonance electrode 31c.

Abstract: A signal transmission device includes: a first substrate and a second substrate disposed to oppose each other in a first direction; a first resonator including a plurality of first quarter wavelength resonators provided in a first region of the first substrate, and interdigitally coupled to one another in the first direction, and a single or the plurality of second quarter wavelength resonators provided in a region of the second substrate corresponding to the first region and interdigitally coupled to one another in the first direction; and a second resonator electromagnetically coupled to the first resonator, and performing a signal transmission between the second resonator and the first resonator. The first and the second quarter wavelength resonators located at positions nearest to one another in the first resonator, respectively have open ends which are disposed to oppose one another, and respectively have short-circuit ends which are disposed to oppose one another.

Abstract: A resonance device is disclosed. The resonance device in accordance with an embodiment of the present invention includes: a case including a first ground surface and a second ground surface which face each other; a stacked part formed inside the case by stacking a first conductive layer and a second conductive layer, wherein the first conductive layer is grounded to the first ground surface and the second conductive layer is separated from the first conductive layer without being grounded to the first ground surface; and a transmission layer connecting the second conductive layer to the second ground surface.

Abstract: A low pass filter includes a signal transmission line, a first open stub, a second open stub, a first coupling line, and a second coupling line. The signal transmission line is connected between a first port and a second port, and operable to transmit RF signals from the first port to the second port. The signal transmission line defines a first side and a second side opposite to the first side. The first open stub and the second stub are disposed on the first side and perpendicularly connected to the signal transmission line. The second open stub and the first open stub co-define a T-shaped gap. The first coupling line is parallel to the signal transmission line and disposed in the T-shaped gap. The second coupling line is parallel to the signal transmission line and disposed on the second side of the signal transmission line.

Abstract: Methods and devices for phase shifting an RF signal for a base station antenna are provided. The device includes a transmission line that has a stationary ground plane coupled to the top of a substrate and a signal line on the bottom of the substrate. The signal line has an input port and an output port. The input port receives the RF signal with a certain phase and travels across the bottom of the substrate to the output port. The RF signal has a different phase at the output port because defected ground structures etched on the stationary ground plane shift the phase of the RF signal. In addition, the device includes a movable ground plane that may cover a portion of the defected ground structures, the substrate, and the stationary ground plane such that the moveable ground plane further adjusts the phase of the RF signal.

Abstract: A narrowband filter tuned at a center frequency. The filter comprises an input terminal, an output terminal, and a plurality of resonators coupled in cascade between the input terminal and the output terminal. Each of the resonators is tuned at a resonant frequency substantially equal to the center frequency. The resonant frequencies of a primary set of the resonators and a secondary set of the resonators are of different orders.

Abstract: Microstrip filters and methods of operation are described. In one aspect, a filter includes a substrate having a substantially planar surface and a microstrip patch located on the surface of the substrate. The microstrip patch includes multiple symmetric slots in the microstrip patch, a first feed line extending from the microstrip patch, and a second feed line extending from the microstrip patch. The first and second feed lines are asymmetric.

Abstract: A multifunction semiconductor package structure includes a substrate unit, a circuit unit, a support unit, a semiconductor unit, a package unit and an electrode unit. The substrate unit includes a substrate body and a first electronic element having a plurality of conductive contact portions. The circuit unit includes a plurality of first conductive layers disposed on the substrate body. The semiconductor unit includes a plurality of second electronic elements. Each second electronic element is electrically connected between two corresponding first conductive layers. The package unit includes a package body disposed on the substrate body to enclose the second electronic elements. The electrode unit includes a plurality of top electrodes, a plurality of bottom electrodes, and a plurality of lateral electrodes electrically connected between the top electrodes and the bottom electrodes.

Abstract: The present disclosure relates to reducing unwanted RF noise in a printed circuit board (PCB) containing an RF device. An isolation filter is embedded in a PCB containing an RDF device. By placing the isolation filter as close as possible to the RF device in order to dramatically reduce unwanted RF noise due to unavoidable coupling between Vias and planes in the PCB structure.

Abstract: Embodiments of the present invention disclose a filter, including: a conductive box body, and an insulating substrate, a first conductor, and a second conductor that are arranged inside the conductive box body. The insulating substrate includes a first surface and a second surface. The first conductor is arranged on the first surface of the insulating substrate. A position on the second surface corresponding to the first conductor contacts with the conductive box body. The second conductor is arranged on the first surface or the second surface of the insulating substrate. The second conductor and the conductive box body form a coaxial resonant cavity together. Further, an end of the second conductor is coupled with the first conductor, and the other end of the second conductor is coupled with the conductive box body. The filter has advantages of a microstrip filter of simple manufacturing process and small volume.

Abstract: A wideband high frequency bandpass filter uses a metamaterial transmission line composed of an open-circuit resonator and a short-circuit resonator to realize a bandpass filter at the band of 60 GHz. The bandpass filter has an ultra-wide passband resulting from the coupling of the two resonators in the resonant modes thereof. The ultra wide passband formed by resonance coupling includes a left-handed passband and a right-handed passband. The two passbands jointly provides a passband ranging from 57.4 GHz to 63.6 GHz and having a bandwidth of 6.2 GHz. The stopbands of the bandpass filter are respectively extended downward from 57.4 GHz to the DC current and extended upward from 63.6 GHz to 109.4 GHz. The bandpass filter of the present invention can be applied to wireless transmission at the band of 60 GHz.

Abstract: A wide-band balun device includes a first metallization deposited over a substrate and oriented in a first coil. The first coil extends horizontally across the substrate while maintaining a substantially flat vertical profile. A second metallization is deposited over the substrate and oriented in a second coil. The second coil is magnetically coupled to the first coil and a portion of the second coil oriented interiorly of the first coil. A third metallization is deposited over the substrate and oriented in a third coil. The third coil is magnetically coupled to the first and second coils. A first portion of the third coil is oriented interiorly of the second coil. The third coil has a balanced port connected to the third coil between second and third portions of the third coil.

Abstract: A transmission line resonator includes distributed coupled lines including first distributed constant line which one ends are connected to a short-circuit grounding portion and second distributed constant line which is disposed in parallel to the first distributed constant line while being separated therefrom by a predetermined distance and which one ends opposing the short-circuit grounded one ends of the first distributed constant line are connected to the short-circuit grounding portion, and a single transmission line which both ends are connected to the respective other ends of the distributed coupled lines.

Abstract: A signal transmission device includes substrates and resonance sections resonating at the predetermined resonance frequency. At least one of the substrates is formed with two or more resonators in the second direction, and the remaining one or two or more of the substrates are each formed with one or more resonators in the second direction, and at least one of the resonance sections is configured by a plurality of resonators opposing one another in the first direction between the substrates, the opposing resonators form a coupled resonator resonating as a whole at the predetermined resonance frequency through electromagnetic coupling in a hybrid resonance mode, and in a state that the substrates are separated away from one another to fail to establish electromagnetic coupling thereamong, the resonators forming the coupled resonator resonate at any other resonance frequency different from the predetermined resonance frequency on the substrate basis.

Abstract: 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.

Abstract: A DC-DC converter includes an insulating substrate with an inductor provided on the top surface thereof, a switching control IC provided therein, and a ground electrode pattern provided on the bottom surface thereof. The ground electrode pattern includes a first pattern and a second pattern separated from each other and a bridge pattern that connects the first and second patterns to each other. A capacitor and the switching control IC is connected to each of the first and second patterns. The bridge pattern faces the inductor and has a smaller width than that of the first and second patterns.

Abstract: Terahertz metamaterials comprise a periodic array of resonator elements disposed on a dielectric substrate or thin membrane, wherein the resonator elements have a structure that provides a tunable magnetic permeability or a tunable electric permittivity for incident electromagnetic radiation at a frequency greater than about 100 GHz and the periodic array has a lattice constant that is smaller than the wavelength of the incident electromagnetic radiation. Microfabricated metamaterials exhibit lower losses and can be assembled into three-dimensional structures that enable full coupling of incident electromagnetic terahertz radiation in two or three orthogonal directions. Furthermore, polarization sensitive and insensitive metamaterials at terahertz frequencies can enable new devices and applications.

Abstract: A wide-band balun device includes a first metallization deposited over a substrate and oriented in a first coil. The first coil extends horizontally across the substrate while maintaining a substantially flat vertical profile. A second metallization is deposited over the substrate and oriented in a second coil. The second coil is magnetically coupled to the first coil and a portion of the second coil oriented interiorly of the first coil. A third metallization is deposited over the substrate and oriented in a third coil. The third coil is magnetically coupled to the first and second coils. A first portion of the third coil is oriented interiorly of the second coil. The third coil has a balanced port connected to the third coil between second and third portions of the third coil.

Abstract: A compact microwave distributed-element dual-mode bandpass filter is provided, comprising a dual-mode resonator and a signal input port and a signal output port coupled electrically to the dual-mode resonator respectively; wherein, the dual-mode resonator comprises a main stripline with a center-loaded short-circuited stub, the main stripline is reasonably folded in both vertical and horizontal directions and is reasonably folded into a first layer, a second layer, a third layer and a fourth layer; a symmetrical plane is provided between the second layer and the third layer, while the first layer and the fourth layer are symmetrical to each other relative to the symmetrical plane, the second layer and the third layer are symmetrical to each other relative to the symmetrical plane as well; the center-loaded short-circuited stub is located on the symmetrical plane, and the symmetrical plane can be treated as a virtual ground at odd-mode resonant frequency.

Abstract: A voltage controlled oscillator includes a split ring resonator (SRR) configured to have meta-material characteristics fabricated on a board, and an energy compensation circuit configured to cause resonant oscillation of the SRR. The energy compensation circuit is fabricated in the form of an integrated circuit.