Showing papers in "IEEE Microwave and Wireless Components Letters in 2010"
TL;DR: In this article, a textured metal lid consisting of periodically located pins known as a bed of nails is employed for the suppression of parallel plate and cavity modes in shielded microstrip circuits, which has a bandwidth of more than 2:1 and does not interfere much with the microstrip circuit.
Abstract: The suppression of parallel plate and cavity modes in shielded microstrip circuits is presented. To this aim a textured metal lid consisting of periodically located pins known as a bed of nails is employed. The mode suppression has a bandwidth of more than 2:1, and it does not interfere much with the microstrip circuit. Thereby, this mode suppression technique introduces a new advantageous packaging technology for high frequency circuits.
181 citations
TL;DR: In this article, a multilayer slotline power divider with bandpass filtering response is presented, in which a single isolation resistor is properly placed between the two output ports.
Abstract: A novel ultra-wideband (UWB) multilayer slotline power divider with bandpass filtering response is presented. In the proposed structure, a single isolation resistor is properly placed between the two output ports. Based on the transmission-line equivalent-circuit method, the design equations of the proposed UWB power divider has been derived with the even and odd mode analyses. Experimental results show that excellent impedance matching at all three ports, amplitude and phase balance at the two output ports, isolation between the two output ports, and out-of-band rejection are observed at the UWB band.
180 citations
TL;DR: In this paper, the authors present a load-loaded transmission line with a constant phase shift over a wide bandwidth, referenced to a uniform transmission line, which shows good performance with simplicity in both design and fabrication.
Abstract: This letter presents a novel loaded transmission line, which has a constant phase shift over a wide bandwidth, referenced to a uniform transmission line. Compared with the conventional coupled line phase shifter, the configuration shows good performance with simplicity in both design and fabrication. The optimal design parameters for different phase shift values up to 120° are also presented to allow for a quick design process. To verify the configuration, a 90° phase shifter using a T shaped open stub loaded transmission line is designed, fabricated and measured. Excellent performance is achieved with small insertion loss and phase deviation over a bandwidth of 82%.
164 citations
TL;DR: In this article, a compact microstrip diplexer with very high output isolation is proposed, which consists of compact hybrid resonators, which are capable of introducing transmission zeros at desired frequencies and meanwhile suppressing signals below the resonant frequencies through tapping the feeding line close to the shorted vias.
Abstract: In this letter, a compact microstrip diplexer with very high output isolation is proposed. This diplexer consists of compact hybrid resonators, which are capable of introducing transmission zeros at desired frequencies and meanwhile suppressing signals below the resonant frequencies through tapping the feeding line close to the shorted vias. By designing the transmission zero of the lower-frequency channel in the higher passband, and utilizing the high lower-stopband suppression property of the higher-frequency channel, very high diplexer output isolation can be achieved. The proposed diplexer with center frequencies at 1.8 and 2.45 GHz, respectively, has demonstrated better than 55 dB output isolation and more than 55 dB suppressions in the stopbands. Furthermore, the diplexer occupies only a small area of 0.13λ0 × 0.2λ0.
152 citations
TL;DR: In this paper, a quasi-optical broadband terahertz detector using a zero bias Schottky diode mounted on a self-complimentary sinuous antenna has been developed.
Abstract: A quasi-optical broadband terahertz detector using a zero bias Schottky diode mounted on a self-complimentary sinuous antenna has been developed. Design and characterization of this detector are described. Measurements show that a responsivity of 300-1000 V/W covering the frequency range of 150-440 GHz has been achieved. The detector performance has been compared to waveguide detectors covering four frequency bands up to 600 GHz. A recent measurement at 600-900 GHz yielded the same output voltage as a waveguide detector. The noise equivalent power level of this detector is estimated to be 5-20 pW/√(Hz) based on the measurements of similar detectors.
151 citations
TL;DR: In this paper, a novel balanced dual-band bandpass filter, using coupled stepped-impedance resonators (SIRs), is proposed, and the differential and common-mode equivalent half circuits are given.
Abstract: A novel balanced dual-band bandpass filter, using coupled stepped-impedance resonators (SIRs), is proposed in this letter. The differential- and common-mode equivalent half circuits are given. By properly designing the resonators, associated with the filter composed of eight SIRs, dual-band differential-mode bandpass response can be obtained. To improve the common-mode suppression level, two open stubs with different lengths are added to the connection point of two resonators. A prototype balanced filter operating at 2.4 and 5 GHz has been realized to validate the proposed concept and theory.
131 citations
TL;DR: In this paper, an ultra wideband bandpass filter using stub-loaded resonator (SISLR) is presented, which has the advantage of providing more degrees of freedom to adjust the resonant frequencies and two transmission zeros can be created at both lower and upper sides of the passband.
Abstract: In this letter, an ultra-wideband (UWB) bandpass filter (BPF) using stepped-impedance stub-loaded resonator (SISLR) is presented. Characterized by theoretical analysis, the proposed SISLR is found to have the advantage of providing more degrees of freedom to adjust the resonant frequencies. Besides, two transmission zeros can be created at both lower and upper sides of the passband. Benefiting from these features, a UWB BPF is then investigated by incorporating this SISLR and two aperture-backed interdigital coupled-lines. Finally, this filter is built and tested. The simulated and measured results are in good agreement with each other, showing good wideband filtering performance with sharp rejection skirts outside the passband.
128 citations
TL;DR: A tri-band bandpass filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this article, where the DGS resonator on the lower plane constructs the first pass-band and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to provide the coupling between the SLRs.
Abstract: A tri-band bandpass filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-band, and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to provide the coupling between the SLRs. The three pass-bands are combined together with a common T-shaped feed line, and a reasonable tuning method is adopted to tune the three pass-bands with smooth responses. A compact tri-band filter with three pass-bands centered at 2.45, 3.5, and 5.25 GHz is designed and fabricated. The measurement results agree well with the full-wave electromagnetic designed responses.
121 citations
TL;DR: In this paper, double-sided parallelstrip line (DSPSL) was used to build a novel differential filter with ultra- wideband (UWB) response, and swap structures, based on DSPSL, are employed in the design to realize 180° phase shift.
Abstract: In this letter, double-sided parallel-strip line (DSPSL) has been used to build a novel differential filter with ultra- wideband (UWB) response. Swap structures, based on DSPSL, are employed in the design to realize 180° phase shift. So the swap structures can realize the conversion between differential- and common-mode. Utilizing the characteristic, the input common- mode signals will be cancelled at the center of the filter, while the input differential-mode signals can propagate in the proposed filter. The proposed new differential filter was calculated in analytical method, and was simulated by the full-wave electromagnetic simulator, and was validated by the measurement. The last results show they have a good in-band and out-band performance. With fractional bandwidth of 110% centered at 3 GHz, the differential-mode signals can propagate with UWB frequency response, while the common-mode signals are suppressed below -20 dB in the whole frequency band.
117 citations
TL;DR: In this article, a compact planar tri-band bandpass filter with high selectivity is proposed, which employs two sets of resonators, i.e., stub-loaded resonators and half-wavelength resonators.
Abstract: This letter presents a compact planar tri-band bandpass filter with high selectivity. The proposed filter employs two sets of resonators, i.e., stub-loaded resonators and half-wavelength resonators. The former is designed to operate at the first and third passbands and the latter at the second passband. The passband frequencies can be conveniently tuned to desired values. One set of resonators is embedded in the other and thus the filter is compact in size. On each side of each passband, there is at least one transmission zero, resulting in high skirt selectivity. For validation, a demonstration filter is implemented. The design methodology and the experimental results are presented.
113 citations
TL;DR: In this paper, a balanced dual-band band-pass filter (BPF) using four coupled bi-section halfwavelength (?/2) stepped-impedance resonators (SIRs) is presented.
Abstract: A new fourth-order balanced dual-band band-pass filter (BPF) designed using four coupled bi-section half-wavelength (?/2) stepped-impedance resonators (SIRs) is presented. To obtain the required differential-mode (DM) operation with suppressed common-mode (CM) transmission, the SIRs were designed to have the same odd-mode, but different even-mode, resonant frequencies. For that purpose, the two inner SIRs were loaded at the center with T-shaped open stubs of different dimensions so that their even-mode resonant frequencies are shifted away from those of the outer SIRs and that their odd-mode ones remain almost intact. For the fabricated prototype BPF, the measured minimum DM insertion losses for the first and second bands are 2.4 and 2.82 dB, respectively, whereas the measured CM insertion loss is larger than 25 dB in 1-7 GHz.
TL;DR: In this article, a miniaturized dual-mode dual-band ring resonator bandpass filter is implemented by a cascade of several microwave C-sections, each C-section is used to substitute a transmission line section of designated electrical length.
Abstract: A new miniaturized dual-mode dual-band ring resonator bandpass filter is implemented by a cascade of several microwave C-sections. Each C-section is used to substitute a transmission line section of designated electrical length. Through proper design of input/output coupling configuration, two transmission zeros can be created on both sides of each passband. Two circuits with four and six microwave C-sections are fabricated for confirmation. They occupy less than 30% of the area of a traditional ring resonator filter. Measured responses agree very well with the simulation.
TL;DR: In this article, the authors present an amplifier module operating at a frequency of 0.48 THz, which represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date.
Abstract: In this letter, we present an amplifier module operating at a frequency of 0.48 THz. This represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date. The amplifier demonstrates a peak gain of 11.7 dB measured in a waveguide split-block housing. Sub 50-nm InP HEMT transistors with an estimated f MAX > 1 THz are used to achieve this level of performance. The five stage amplifier is realized in coplanar waveguide, and uses monolithically integrated dipole probes to couple the chip from the WR 2.2 waveguide.
TL;DR: In this article, a new type of compact wideband bandstop filter (BSF) with four transmission zero in the stopband is presented. And the proposed filter topology consists of a coupled line directional coupler connected in parallel to an interference transmission line.
Abstract: This work presents a new type of compact wideband bandstop filter (BSF) with four transmission zeros in the stopband. The proposed filter topology consists of a coupled line directional coupler connected in parallel to an interference transmission line. The filter characteristics can be easily controlled by the coupling factor of the coupled line coupler and the characteristic admittances of both the coupler and the transmission line. Design equations and curves are provided for the filter design. To validate the proposed topology, a compact microstrip BSF centered at 2.0 GHz with a measured 20 dB rejection bandwidth of 100% and sharp rejection characteristics is designed and built.
TL;DR: In this paper, a new technique for designing tunable frequency selective surfaces (FSSs) with the second-order band-pass response is presented and experimentally verified, which is applied to an FSS utilizing nonresonant, subwavelength, constituting unit cells.
Abstract: In this letter, a new technique for designing tunable frequency selective surfaces (FSSs) with the second-order band-pass response is presented and experimentally verified. The technique is applied to an FSS utilizing nonresonant, subwavelength, constituting unit cells. Frequency tuning is achieved by adjusting the location of a liquid metal slug within capillary tubes embedded between the FSS's metallic layers. A wideband flexible frequency tuning covering nearly the entire X band is tested in a waveguide environment and excellent agreement between the measured and simulated results is demonstrated.
TL;DR: In this article, a printable chipless tag with electromagnetic code using split ring resonators is proposed, which can be applied to paper/plastic-based items such as ID cards, tickets, banknotes and security documents.
Abstract: In this letter, a printable chipless tag with electromagnetic code using split ring resonators is proposed. A 4 b chipless tag that can be applied to paper/plastic-based items such as ID cards, tickets, banknotes and security documents is designed. The chipless tag generates distinct electromagnetic characteristics by various combinations of a split ring resonator. Furthermore, a reader system is proposed to digitize electromagnetic characteristics and convert chipless tag to electromagnetic code.
TL;DR: In this paper, a cross-coupled bandpass filter using new substrate integrated waveguide (SIW) resonators is presented, which is built up by a SIW cavity loaded with a complementary split-ring resonator on its top metal plane.
Abstract: A novel cross-coupled bandpass filter using new substrate integrated waveguide (SIW) resonators is presented. The resonator is built up by a SIW cavity loaded with a complementary split-ring resonator (CSRR) on its top metal plane. The resonant modes of the proposed resonator are analyzed, with the Q-factor of the dominant mode also extracted. It is shown that our proposed compact filter operates below the cutoff frequency of conventional SIWs. No spurious responses, corresponding to the higher-order resonant modes of the resonator, appear within an octave band of the central frequency. Its attractive performance is validated numerically and experimentally.
TL;DR: In this paper, an asymmetric coupling strip is presented, which can be used in the ultra wideband (UWB) bandpass filter (BPF) to generate multiple notched bands within the passband.
Abstract: A novel asymmetric coupling strip is presented, which can be used in the ultra-wideband (UWB) bandpass filter (BPF) to generate multiple notched bands within the passband. The proposed structure can provide two main paths for the signals, which makes it possible to generate multiple transmission zeroes. The center frequencies and bandwidths of the notched bands can be controlled by tuning the structural parameters. The asymmetric coupling strip has been integrated into a circular disc resonator to construct a compact UWB BPF with multiple notched bands. The measured results agree with the predicted ones closely. These two notched bands centered at 4.3 and 8 GHz have 10-dB rejection fractional bandwidths of about 4.2% and 3.8%, respectively.
TL;DR: In this article, the improved CPW-fed configurations with dual-mode double-square-ring resonators (DMDSRR) for quad-band applications were proposed, where the resonant frequency equations of DMDSRR are introduced for simply designing a quadband bandpass filter (BPF).
Abstract: We propose the improved CPW-fed configurations with dual-mode double-square-ring resonators (DMDSRR) for quad-band applications. The resonant frequency equations of DMDSRR are introduced for simply designing quad-band bandpass filter (BPF). Resonant frequencies can be controlled by tuning the perimeter ratio of the square rings. To obtain lower insertion loss, higher out-of-band rejection level and wider bandwidth of quad-band, the improved CPW-fed and dual-mode perturbations are designed. The proposed filter is successfully simulated and measured. It can be applied to 0.95, 1.26, 1.89 and 2.29 GHz systems.
TL;DR: In this paper, a compact microstrip ultrawideband (UWB) bandpass filter (BPF) with a narrow notched band in the UWB passband is presented.
Abstract: A compact microstrip ultrawideband (UWB) bandpass filter (BPF) with a narrow notched band in the UWB passband is presented. The narrow notched band was introduced by using a new technique that involves embedding a parasitic coupled line to the UWB BPF in order to reject any undesired existing radio signal that may interfere with the determined UWB passband. The notched band can be easily generated and set at any desired frequency by varying the structural parameters of parasitic coupled line. The design is successfully realized in theory and verified by electromagnetic (EM) simulation and the experiment. This filter can be integrated in UWB radio systems and efficiently enhance the interference immunity from undesired signals such as wireless local area network (WLAN).
TL;DR: In this article, a compact lowpass filter with two transmission zeros is presented, which can be adjusted easily to obtain a larger zero separation without the need to change the stepped-impedance unit.
Abstract: This letter presents a novel compact lowpass filter with two transmission zeros. By tap-connecting the stepped-impedance hairpin unit, two transmission zeros can be generated when an interdigital structure is introduced between the two low-impedance sections. Further, the two transmission zeros can be adjusted easily to obtain a larger zero separation without the need to change the stepped-impedance unit. Therefore, a sharp transition, an expanded stopband, a low insertion loss, and a compact size can be obtained simultaneously. Two filters with single and two asymmetric units are designed, fabricated, and tested. The measured results demonstrate good performance: compact size, low passband insertion loss, broad stopband, and sharp skirt characteristic.
TL;DR: In this paper, four kinds of basic structures (outer-frame, U-shaped resonator, modified end-coupled microstrip line, and defected ground structures) are combined to develop a miniature quad-band bandpass filter on a MgTa1.5Nb0.5O6 microwave ceramic substrate.
Abstract: By the use of screen-printing technique, four kinds of basic structures (outer-frame, U-shaped resonator, modified end-coupled microstrip line, and defected ground structures) are combined to develop a miniature quad-band bandpass filter on a MgTa1.5Nb0.5O6 microwave ceramic substrate. The operating frequencies are designed for the applications of the modern GPS (1.57 GHz), WiMAX (3.5 GHz) and WLAN (2.45/5.2 GHz) systems, and the design procedures are discussed in detail and both of the simulated and measured results are presented.
TL;DR: In this article, a compact ultra wideband (UWB) bandpass filter with an ultra narrow notched band is proposed using a hybrid microstrip and coplanar waveguide (CPW) structure.
Abstract: A compact ultra-wideband (UWB) bandpass filter with an ultra narrow notched band is proposed using a hybrid microstrip and coplanar waveguide (CPW) structure. The CPW detached-mode resonator (DMR) composed of a quarter-wavelength (?/4) nonuniform CPW resonator with a short-stub and a ?/4 single-mode CPW resonator (SMCR) can allocate three split frequencies at the lower end, middle, higher end of the UWB passband. The conventional broadside-coupled microstrip/CPW structure is introduced to improve the bandwidth enhancement around the split frequencies, which leads to good UWB operation. To avoid the interferences such as WLAN signals, the ?/4 meander slot-line structure embedded in the DMR is employed to obtain the notched band inside the UWB passband. The design is then verified by experiment. Good passband and stopband performances are achieved. Specifically, the fabricated filter has a 10 dB notched fractional bandwidth (FBW) of 2.06% at the notched center frequency of 5.80 GHz.
TL;DR: In this article, the design and RF packaging of a substrate integrated widely tunable filter is presented, which consists of two heavily loaded evanescentmode cavities embedded into the substrate.
Abstract: In this letter, the design and RF packaging of substrate integrated widely tunable filter is presented. The filter consists of two heavily loaded evanescent-mode cavities embedded into the substrate. The filter is actuated using two piezoelectric discs, which move thin, flexible membranes that form the top of the cavities. To demonstrate the wide tuning a filter is fabricated and measured to cover a very wide frequency range from 0.98 to 3.48 GHz (tuning ratio-3.55:1). The measured insertion loss is less than 3.57 dB for a 1.1% fractional bandwidth filter.
TL;DR: In this paper, the authors present an algebraic expression for the problem of finding the minimum number of elements in a graph to be a function of the number of nodes in the graph.
Abstract: Equations (2) and (3) in the above titled paper (ibid., vol. 17, no. 6, pp. 415-417, Jun. 07) should read as presented here.
TL;DR: In this paper, an ultrawideband common-gate low noise amplifier with tunable interference rejection is presented, which embeds a tunable active notch filter to eliminate interferer at 5 GHz WLAN and employs a commongate input stage and dual-resonant loads for wideband implementation.
Abstract: An ultrawideband common-gate low noise amplifier with tunable interference rejection is presented. The proposed LNA embeds a tunable active notch filter to eliminate interferer at 5-GHz WLAN and employs a common-gate input stage and dual-resonant loads for wideband implementation. This LNA has been fabricated in a 0.18-?m CMOS process. The measured maximum power gain is 13.2 dB and noise figure is 4.5-6.2 dB with bandwidth of 3.1-10.6 GHz. The interferer rejection is 8.2 dB compared to the maximum gain and 7.6 dB noise figure at 5.2 GHz , respectively. The measured input P1dB is -11 dBm at 10.3 GHz. It consumes 12.8 mA from 1.8-V supply voltage.
TL;DR: A 1-9 GHz linear-wide-tuning-range quadrature ring oscillator has been designed and fabricated in UMC 0.13?m CMOS process.
Abstract: A 1-9 GHz linear-wide-tuning-range quadrature ring oscillator has been designed and fabricated in UMC 0.13 ?m CMOS process. The chip was wire-bonded on printed circuit board and tested, showing a liner tuning range from 1 GHz to 9 GHz. Comparative study with other differential ring oscillators demonstrates the advantages of this design in low power consumption and linear-tuning. The oscillator was designed as the voltage controlled oscillator (VCO) for a non-contact vital sign radar sensor. It can also be used for other applications such as ultra-wideband (UWB) impulse radio and clock recovery in broadband optical communications.
TL;DR: In this article, a bandpass filter with improved upper stopband performance using a defected ground structure (DGS) is presented, which is composed of seven DGSs that are positioned under the input and output microstrip line and coupled double step impedance resonator (CDSIR).
Abstract: A novel ultra-wideband (UWB) bandpass filter (BPF) with improved upper stopband performance using a defected ground structure (DGS) is presented in this letter. The proposed BPF is composed of seven DGSs that are positioned under the input and output microstrip line and coupled double step impedance resonator (CDSIR). By using CDSIR and open loop defected ground structure (OLDGS), we can achieve UWB BPF characteristics, and by using the conventional CDGSs under the input and output microstrip line, we can improve the upper stopband performance. Simulated and measured results are found in good agreement with each other, showing a wide passband from 3.4 to 10.9 GHz, minimum insertion loss of 0.61 dB at 7.02 GHz, a group delay variation of less than 0.4 ns in the operating band, and a wide upper stopband with more than 30 dB attenuation up to 20 GHz. In addition, the proposed UWB BPF has a compact size (0.27?g ~ 0.29?g , ?g : guided wavelength at the central frequency of 6.85 GHz).
TL;DR: In this paper, a novel ultra wideband (UWB) bandpass filter using two shorted coupled lines and a 270° transversal transmission line is proposed, which achieves good impedance matching, UWB passband and wider upper stopband.
Abstract: A novel ultra-wideband (UWB) bandpass filter using two shorted coupled lines and a 270° transversal transmission line is proposed. The two shorted coupled lines are utilized to realize 180° phase inversion, while a folded transversal transmission line of 270° is introduced to perform as another power transmission path. Good impedance matching, UWB passband and wider upper stopband can be achieved. One prototype is fabricated for demonstration, good agreement is observed between simulated and measured performances of the UWB filter, indicating a fractional bandwidth of 124.6% (3-11.6 GHz).
TL;DR: In this article, a novel quintuple-mode stub-loaded resonator and ultrawideband (UWB) bandpass filter (BPF) are proposed, which can generate two odd modes and three even modes in the desired band.
Abstract: A novel compact quintuple-mode stub-loaded resonator and ultrawideband (UWB) bandpass filter (BPF) are proposed in this letter. The proposed resonator can generate two odd modes and three even modes in the desired band. The odd-mode resonance frequencies are exclusively correlated to the modified triple-mode resonator; even-mode resonance frequencies can be flexibly controlled by the impedance-stepped open and short stub at its central plane, whereas the odd-mode ones are fixed. The open stubs in pairs at two sides of the low-impedance line are mainly applied to adjust the high resonant modes (fm4, fm5) into desired passband. The short stub can generate two transmission zeros near the lower and upper cutoff frequencies, leading to high rejection skirt. A quintuple-mode UWB filter is simulated, fabricated, and measured. The EM simulated and measured results are presented, and an excellent agreement is obtained.