Showing papers on "Insertion loss published in 2003"
TL;DR: In this article, the authors present new concepts that allow for the complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metallized post (or via-hole) arrays.
Abstract: The integrated planar technique has been considered as a reliable candidate for low-cost mass production of millimeter-wave circuits and systems. This paper presents new concepts that allow for a complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metallized post (or via-hole) arrays. Analysis of the synthesized integrated waveguide and design criteria are presented for the post pitch and diameter. A filter design method derived from a synthesis technique using inductive post is presented. An experimental three-pole Chebyshev filter having 1-dB insertion loss and return loss better than 17 dB is demonstrated. Integrating such planar and nonplanar circuits on a substrate can significantly reduce size, weight, and cost, and greatly enhance manufacturing repeatability and reliability.
868 citations
TL;DR: Both transducer focusing techniques proved successful in producing highly sensitive, high-frequency, single-element, ultrasonic-imaging transducers that could possibly allow for an increase in depth of penetration, higher image signal-to-noise ratio (SNR), and improved image contrast at high frequencies when compared to previously reported results.
Abstract: This paper discusses the design, fabrication, and testing of sensitive broadband lithium niobate (LiNbO/sub 3/) single-element ultrasonic transducers in the 20-80 MHz frequency range. Transducers of varying dimensions were built for an f# range of 2.0-3.1. The desired focal depths were achieved by either casting an acoustic lens on the transducer face or press-focusing the piezoelectric into a spherical curvature. For designs that required electrical impedance matching, a low impedance transmission line coaxial cable was used. All transducers were tested in a pulse-echo arrangement, whereby the center frequency, bandwidth, insertion loss, and focal depth were measured. Several transducers were fabricated with center frequencies in the 20-80 MHz range with the measured -6 dB bandwidths and two-way insertion loss values ranging from 57 to 74% and 9.6 to 21.3 dB, respectively. Both transducer focusing techniques proved successful in producing highly sensitive, high-frequency, single-element, ultrasonic-imaging transducers. In vivo and in vitro ultrasonic backscatter microscope (UBM) images of human eyes were obtained with the 50 MHz transducers. The high sensitivity of these devices could possibly allow for an increase in depth of penetration, higher image signal-to-noise ratio (SNR), and improved image contrast at high frequencies when compared to previously reported results.
321 citations
TL;DR: In this paper, a miniature three-pole filter with 8.6% bandwidth based on high-Q MEMS bridge capacitors was developed for tunable bandpass filters at 18-22 GHz.
Abstract: Microelectromechanical system (MEMS) bridge capacitors have been used to design miniature and tunable bandpass filters at 18-22 GHz. Using coplanar waveguide transmission lines on a quartz substrate (/spl epsiv//sub r/ = 3.8, tan/spl delta/ = 0.0002), a miniature three-pole filter was developed with 8.6% bandwidth based on high-Q MEMS bridge capacitors. The miniature filter is approximately 3.5 times smaller than the standard filter with a midband insertion loss of 2.9 dB at 21.1 GHz. The MEMS bridges in this design can also be used as varactors to tune the passband. Such a tunable filter was made on a glass substrate (/spl epsiv//sub r/ = 4.6, tan/spl delta/ = 0.006). Over a tuning range of 14% from 18.6 to 21.4 GHz, the miniature tunable filter has a fractional bandwidth of 7.5 /spl plusmn/ 0.2% and a midband insertion loss of 3.85-4.15 dB. The IIP/sub 3/ of the miniature-tunable filter is measured at 32 dBm for the difference frequency of 50 kHz. The IIP/sub 3/ increases to >50 dBm for difference frequencies greater than 150 kHz. Simple mechanical simulation with a maximum dc and ac (ramp) tuning voltages of 50 V indicates that the filter can tune at a conservative rate of 150-300 MHz//spl mu/s.
289 citations
TL;DR: Tunable lowpass and bandpass lumped-element filters employing barium-strontium-titanate (BST)-based capacitors are presented in this paper, where a new metallization technique is used, which improves the quality factor of the tunable BST capacitors by a factor of two.
Abstract: Tunable lowpass and bandpass lumped-element filters employing barium-strontium-titanate (BST)-based capacitors are presented A new metallization technique is used, which improves the quality factor of the tunable BST capacitors by a factor of two The lowpass filter has an insertion loss of 2 dB and a tunability of 40% (120-170 MHz) with the application of 0-9 V DC bias The bandpass filter (BPF) has an insertion loss of 3 dB and a tunability of 57% (176-276 MHz) with the application of 0-6 V DC The third-order intercept point of the BPF was measured to be 19 dBm with the application of two tones around 170 MHz
255 citations
TL;DR: In this paper, a 50/spl Omega/ coplanar waveguide with split ring resonators (SRRs) etched in the back side of the substrate is presented, with the result of a sharp and narrow rejection band in the vicinity of the resonant frequency of the rings.
Abstract: A novel compact stop band filter consisting of a 50 /spl Omega/ coplanar waveguide (CPW) with split ring resonators (SRRs) etched in the back side of the substrate is presented. By aligning SRRs with the slots, a high inductive coupling between line and rings is achieved, with the result of a sharp and narrow rejection band in the vicinity of the resonant frequency of the rings. In order to widen the stop band of the filter, several ring pairs tuned at equally spaced frequencies within the desired gap are cascaded. The frequency response measured in the fabricated prototype device exhibits pronounced slopes at either side of the stop band and near 0 dBs insertion loss outside that band. Since SRR dimensions are much smaller than signal wavelength, the proposed filters are extremely compact and can be used to reject frequency parasitics in CPW structures by simply patterning properly tuned SRRs in the back side metal. Additional advantages are easy fabrication and compatibility with MMIC or PCB technology.
237 citations
TL;DR: In this article, a microelectromechanical system-based beam steering optical crossconnect switch core with port count exceeding 1100 was presented, featuring mean fiber-to-fiber insertion loss of 2.1 dB and maximum insertion loss 4.0 dB across all possible connections.
Abstract: We present a microelectromechanical systems-based beam steering optical crossconnect switch core with port count exceeding 1100, featuring mean fiber-to-fiber insertion loss of 2.1 dB and maximum insertion loss of 4.0 dB across all possible connections. The challenge of efficient measurement and optimization of all possible connections was met by an automated testing facility. The resulting connections feature optical loss stability of better than 0.2 dB over days, without any feedback control under normal laboratory conditions.
208 citations
TL;DR: In this article, the authors demonstrate fabrication of silica disk microcavities, which exhibit whispering-gallery-type modes having quality factors (Q) in excess of 1 million using standard lithographic techniques.
Abstract: Using standard lithographic techniques, we demonstrate fabrication of silica disk microcavities, which exhibit whispering-gallery-type modes having quality factors (Q) in excess of 1 million. Efficient coupling (high extinction at critical coupling and low, nonresonant insertion loss) to and from the disk structure is achieved by the use of tapered optical fibers. The observed high Q is attributed to the wedged-shaped edge of the disk microcavity, which is believed to isolate modes from the disk perimeter and thereby reduce scattering loss. The mode spectrum is measured and the influence of planar confinement on the mode structure is investigated. We analyze the use of these resonators for very low loss devices, such as add/drop filters.
171 citations
TL;DR: In this paper, a rotary joint design for high-power applications is presented for single-channel waveguide rotary joints, which reduces the diameter of the rotary ring by tapered ridged waveguide sections.
Abstract: A new design for single-channel waveguide rotary joints for high-power applications is presented. In order to obtain correct signal phase conditions along the ring and, at the same time, reduce the diameter of the rotary joint, tapered ridged waveguide sections are introduced. Design guidelines with respect to general transmission characteristics, H-plane aperture couplers, and ridge waveguide analysis are presented. Measurements of a 9.05-GHz prototype show less than 1-dB insertion loss over a 250-MHz bandwidth and, hence, verify the design concept.
164 citations
TL;DR: In this paper, a 2.2-bit coplanar-waveguide phase shifter was developed on a 500/spl mu/m quartz substrate for X-and Ka-band operation.
Abstract: 2-bit wide-band distributed coplanar-waveguide phase shifters have been developed on a 500-/spl mu/m quartz substrate for X- and Ka-band operation. The designs utilize microelectromechanical system (MEMS) switches in a distributed MEMS transmission line periodically loaded by MEMS switches and high Q (/spl ges/250 at 30 GHz) metal-air-metal capacitors. The MEMS switches are actuated by a /spl plusmn/20-V voltage waveform using a high-resistance bias line. Estimated spring constant and switching time is 30 N/m and 9 /spl mu/s, respectively. The Ka-band 2-bit design results in a reflection coefficient better than -11.5 dB, an average insertion loss of -1.5 dB and phase shifts of 0/spl deg/, 89/spl deg/, 180/spl deg/, and 270/spl deg/ at 37.7 GHz. The X-band 2-bit design results in a reflection coefficient better than -12.5 dB, an average insertion loss of -1.2 dB and phase shifts of 0/spl deg/, 94/spl deg/, 176/spl deg/, and 270/spl deg/ at 13.6 GHz. These results are very competitive with switched transmission-line and reflection-based phase shifters. The distributed design can be easily scaled to V- and W-band frequencies for wide-band low-loss performance.
162 citations
TL;DR: In this paper, 2-and 4-bit X-to-K/sub u/-band phase shifters with a very low insertion loss are described, which is achieved using MEMS SP4T switches, which reduce the number of switches in the signal path by half compared to conventional designs with SP2T switches.
Abstract: 2- and 4-bit microelectromechanical system (MEMS) X- to K/sub u/-band true-time-delay phase shifters with a very low insertion loss are described. The phase shifters are fabricated on 200-/spl mu/m GaAs substrates and the low loss is achieved using MEMS SP4T switches, which reduce the number of switches in the signal path by half when compared to conventional designs with SP2T switches. Measurements indicate an insertion loss of -0.6/spl plusmn/0.3 and -1.2/spl plusmn/0.5 dB at 10 GHz for the 2- and 4-bit designs, respectively. The measured losses agreed very well with Momentum simulations and are the lowest reported to date. The 2-bit phase shifter performed well from dc-18 GHz, with -0.8/spl plusmn/0.3-dB insertion loss at 18 GHz and a return loss of <-10.5 dB over dc-18 GHz.
153 citations
TL;DR: An electro-optical switch implemented in coupled photonic crystal waveguides (12, 14) was proposed and analyzed using both a finite-difference time-domain (FDTD) method and a plane wave expansion (PWM) method as discussed by the authors.
Abstract: An electro-optical switch (10) implemented in coupled photonic crystal waveguides (12, 14) is disclosed. The switch (10) is proposed and analyzed using both a finite-difference time-domain ('FDTD') method and a plane wave expansion ('PWM') method. The switch (10) may be implemented in a square lattice (18) of silicon posts in air, as well as in a hexagonal lattice (38) of air holes in a silicon slab. Switching occurs due to a change in the conductance in the coupling region between the photonic crystal waveguides (12, 14), which modulates the coupling coefficient and eventually causes switching. Conductance may be induced electrically by carrier injection or optically by electron-hole pair generation. The electro-optical switch (10) has low insertion loss and optical crosstalk in both the cross and bar switching states.
TL;DR: In this paper, a tunable interdigital coplanar filter with tapped-line feedings is presented, where capacitors are used as a high contrast capacitive switch between a quarter-wavelength resonator and an open-ended stub to perform the frequency shift.
Abstract: This paper presents a tunable interdigital coplanar filter with tapped-line feedings. Microelectromechanical systems capacitors are used as a high contrast capacitive switch between a quarter-wavelength resonator and an open-ended stub to perform the frequency shift. A two-pole tunable filter with a 13% relative bandwidth has been designed, fabricated, and measured. The center frequency can be switched from 18.5 to 21.05 GHz with low return losses (less than 15 dB) and low insertion losses (3.5 dB).
TL;DR: In this article, a via-less coplanar waveguide (CPW) to microstrip transition is discussed and design rules based on simulations and experimental results are presented, which demonstrates a maximum insertion loss of 1 dB over the frequency range from 10 GHz to 40 GHz with a value of 0.4 dB at 20 GHz.
Abstract: A novel via-less coplanar waveguide (CPW) to microstrip transition is discussed and design rules based on simulations and experimental results are presented. This transition demonstrates a maximum insertion loss of 1 dB over the frequency range from 10 GHz to 40 GHz with a value of 0.4 dB at 20 GHz. This transition could find a variety of applications due to its compatibility with RF systems-on-a chip, low loss performance, low cost and its ease of fabrication.
TL;DR: In this paper, an advanced microelectromechanical systems (MEMS) optical switch that consists of actuator, suspension beam, micromirror, and fiber grooves using deep RIE (DRIE) etching fabrication process is described.
Abstract: Optical switch is widely used in the optical fibre communication networks. This paper described an advanced microelectromechanical systems (MEMS) optical switch that consists of actuator, suspension beam, micromirror, and fiber grooves using deep RIE (DRIE) etching fabrication process. Based on the specification and design requirements of optical switch, the DRIE etching fabrication process is combined with the anisotropic and isotropic, the two different types of etching methods that improve the surface roughness of the micro mirror. Net structure with arcs is introduced to obtain a good release and microloading effect is used and prevented trickily. As a result, promising performances of the optical switch such as low driving voltage of 30 V, low insertion loss, fast switching speed of less than 100 μs and high reliable operation of more than 20 million cycles are achieved. The actuator of the optical switch enables to the delivery of a moving displacement which is as large as 45 μm. This MEMS optical switch has a broad applications for fibre optical communication systems such as n×n optical crossconnects (OXCs), variable optical attenuator (VOA), etc.
23 Mar 2003
TL;DR: In this article, a low-loss arrayed-waveguide grating multi-demultiplexer with a crosstalk of 30/spl plusmn/2 dB and an insertion loss of 2.8/spl +mn/0.3 dB is realized.
Abstract: Single-mode perfluoropolymer waveguide structures exhibiting a polarization-independent ultra low loss of <0.05 dB/cm at 1310 nm and <0.07 dB/cm at 1550 nm with a /spl Delta/n of 1.6% have been fabricated for the first time. These new low-loss structures indicate relatively high-power-handling reliability at 1310 and 1550 nm. Based on this, a highly efficient arrayed-waveguide grating multi-demultiplexer with a crosstalk of 30/spl plusmn/2 dB and an insertion loss of 2.8/spl plusmn/0.3 dB is realized.
TL;DR: A high-performance CMOS single-pole double-throw (SPDT) T/R switch for Bluetooth class-II applications has been designed and fabricated in a partially depleted 0.25-/spl mu/m SOI process to compare the influence on losses and isolation of the substrate resistivity.
Abstract: Taking full advantage of the high resistivity substrate and underlying oxide of silicon-on-insulator (SOI) technology, a high-performance CMOS single-pole double-throw (SPDT) T/R switch for Bluetooth class-II applications has been designed and fabricated in a partially depleted 0.25-/spl mu/m SOI process. To compare the influence on losses and isolation of the substrate resistivity, the switch has been integrated above standard and high resistivity (20 /spl Omega//spl middot/cm and 1 k/spl Omega//spl middot/cm) substrates. The switch over the standard resistivity substrate exhibits 1 dB of insertion loss and 45dB of isolation at 2.4 GHz. With the high resistivity substrate, the overall performances are strongly improved until 0.7-dB insertion loss and a 54-dB isolation at 2.4 GHz. At 5 GHz, the switch over the high resistivity substrate keeps insertion loss and isolation at 1 and 46 dB, respectively. In both cases, the measured 1-dB input compression point is 12 dBm. The targeted Bluetooth class-II specifications have been fully fitted.
08 Jun 2003
TL;DR: An electrostatically actuated broadband ohmic microswitch has been developed that has applications from DC through the microwave region as discussed by the authors, which is a 3-terminal device based on a cantilever beam and is fabricated using an all-metal, surface micromachining process.
Abstract: An electrostatically actuated broadband ohmic microswitch has been developed that has applications from DC through the microwave region. The microswitch is a 3-terminal device based on a cantilever beam and is fabricated using an all-metal, surface micromachining process. It operates in a hermetic environment obtained through a wafer-bonding process. Characteristics of the wafer-level packaged switch include DC on-resistance of less than 1 ohm with an actuation voltage of 80 V, lifetime of greater than 10/sup 10/ cycles with on-resistance variation of less than 0.2 Ohm and current handling capability of 1 A. Key RF characteristics at 2 GHz include an insertion loss of 0.32 dB and isolation of 33 dB for our 4-contact microswitch. Preliminary measurements at higher microwave frequencies are extremely promising with full characterization and planned product improvements underway.
TL;DR: In this article, a waveguide-to-microstrip transition with an integrated bias-T is presented, which couples the RF field of a full-height waveguide to a microstrip line or directly to an active component.
Abstract: A novel device, a waveguide-to-microstrip transition with an integrated bias-T, is presented. The substrate-based planar structure comprises a waveguide E-probe, shaped as a radial line. The probe couples the RF field of a full-height waveguide to a microstrip line or directly to an active component, e.g., a transistor or diode in a mixer or direct detector. The radial probe is connected on its wide side to another port via a specially shaped high impedance line that provides RF/DC isolation. This port can then be used to inject DC and/or extract IF signals. The design of the presented structure was done using CAD (3-D EM simulation) and an X-band device was produced and fully characterized. The measured performance is in excellent agreement with the simulations; the device has return loss better than -20 dB, insertion loss less or equal to -0.15 dB and isolation for the bias-T line better than -20 dB. RF bandwidth for the transition is 30% of the central frequency.
Patent•
22 Apr 2003
TL;DR: In this paper, a flexible membrane is used to adjust the capacitance of an electronic circuit by pulling the membrane upwards by means of the bias circuitry, resulting in a large capacitance variation and high Q factor.
Abstract: A device for varying the capacitance of an electronic circuit is disclosed. The device comprises a flexible membrane located above the electronic circuit, a metal layer connected to the flexible membrane, and bias circuitry located above the membrane. Variation of the capacitance of the electronic circuit is obtained by pulling the membrane upwards by means of the bias circuitry. The disclosed device provides a sizeable capacitance variation and high Q factor, resulting in overall low filter insertion loss. A nearly constant group delay over a wide operating bandwidth is also obtained.
TL;DR: In this article, the authors used a broadband, free-space, focused-beam system to measure the transmission and reflection in left-handed-material (LHM) slabs.
Abstract: We used a broadband, free-space, focused-beam system to measure the transmission and reflection in left-handed-material (LHM) slabs. The samples were made of alternating patterns of copper wires and split-ring resonators on Rogers 5880 substrates separated by Rohacell™ spacers. The measured data show very good agreement with numerical simulations. The measured insertion loss of this structure was −1.1 dB/cm at the LHM pass band. Simulations suggest that the loss may be attributable to the finite conductivity of the copper patterns.
TL;DR: In this paper, the optical design and modeling of a 3D MEMS-based optical switch are discussed, and basic design rules and considerations are reviewed and used to determine the optimum configuration for free-space optical switches with more than 300 ports.
Abstract: Photonic cross-connects (PXC) play a key role in all-optical transparent networks. In this paper, the optical design and modeling of a three-dimensional microelectromechanical system (3-D MEMS) based optical switch are discussed. Basic design rules and considerations are reviewed and used to determine the optimum configuration for free-space optical switches with more than 300 ports. The optical performance of a 256 /spl times/ 256 PXC system, including a 347 /spl times/ 347 nonblocking core switch and auxiliary 2 /spl times/ 2 optical switches for 1:1 protection and optical taps for power monitoring, is presented. The core switch has 1.4-dB median insertion loss, 1.5-dB wavelength dependent loss across a broadband of 1260-1625 nm, and a typical polarization dependent loss of 0.1 dB. Environmental tests including temperature and vibration are described.
TL;DR: In this article, the authors present results on Fe-and Permalloy-based microstrip microwave band-stop filters, which are compatible in size and growth process with on-chip highfrequency electronics.
Abstract: We present results on Fe- and Permalloy™-based microstrip microwave band-stop filters. These structures, prepared on GaAs substrates, are compatible in size and growth process with on-chip high-frequency electronics. We observed power attenuation of 100 dB/cm for Permalloy and 180 dB/cm for Fe. The insertion loss is low: 2–3 dB for Permalloy and 3–5 dB for the Fe-based structures. Our geometry includes a significant boost to the zero-field operational frequency due to the shape anisotropy of the magnetic element in the microstrip. Using the shape anisotropy, we create a Fe-based filter that operates at 11 GHz with zero applied field.
TL;DR: In this article, a monolithic Ka-band true-time-delay (TTD) switched-line network containing 12 metal-to-metal contact RF microelectromechanical system switches has been successfully fabricated and characterized on a 75/spl mu/m-thick GaAs substrate.
Abstract: A monolithic Ka-band true-time-delay (TTD) switched-line network containing 12 metal-to-metal contact RF microelectromechanical system switches has been successfully fabricated and characterized on a 75-/spl mu/m-thick GaAs substrate. The compact 9.1-mm/sup 2/ TTD network was designed to produce flat delay time over a dc-to-40-GHz bandwidth with full 360/spl deg/ phase control at 45/spl deg/ intervals at 35 GHz. Measurements show a match to within 2% to the designed delay times at 35 GHz for all eight switch states with 2.2-dB average insertion loss over all states. Peak rms phase error is 2.28/spl deg/ and peak rms amplitude error is 0.28 dB from dc to 40 GHz. Return loss better than 15 dB from dc to 40 GHz for all eight states confirms the circuit's broad-band operation.
TL;DR: The effects of heat-generated changes on the attenuation of ultrasound (US) by porcine liver tissue have been studied over a frequency range of 2.0 to 5.0 MHz and increases of up to 2.4 dB/cm were found.
Abstract: The effects of heat-generated changes on the attenuation of ultrasound (US) by porcine liver tissue have been studied over a frequency range of 2.0 to 5.0 MHz. Samples of fresh tissue, 4- to 5-mm thick, were pressurized and cooled before measurement. The insertion loss was measured at room temperature, using a broadband 3.5-MHz transducer of focal length 10 cm, employing a pulse-reflection technique. Fourier analysis of the results gave the frequency-dependence of the insertion loss. Samples were then heated in a water bath to a temperature in the range of 40 to 80 degrees C, for between 30 and 500 s. The insertion loss was then re-measured at room temperature. The frequency-dependence of the change in insertion loss, expressed as a coefficient, in dB/cm, was fitted by linear regression, from which the attenuation change at 3.5 MHz was determined. This change was attributed to protein coagulation. Increases of up to 2.4 dB/cm, (80 degrees C, 300 s) were found. The averaged data were fitted to a single step exponential model, resulting in a time constant on the order of 118 +/- 5 s, and an asymptotic limit to the increase of attenuation coefficient of 2.67 +/- 0.5 dB/cm.
TL;DR: In this article, two single-pole, double-throw transmit/receive switches were designed and fabricated with different substrate resistances using a 0.18/spl mu/m p/sup $/substrate CMOS process.
Abstract: Two single-pole, double-throw transmit/receive switches were designed and fabricated with different substrate resistances using a 0.18-/spl mu/m p/sup $/substrate CMOS process. The switch with low substrate resistances exhibits 0.8-dB insertion loss and 17-dBm P/sub 1dB/ at 5.825 GHz, whereas the switch with high substrate resistances has 1-dB insertion loss and 18-dBm P/sub 1dB/. These results suggest that the optimal insertion loss can be achieved with low substrate resistances and 5.8-GHz T/R switches with excellent insertion loss and reasonable power handling capability can be implemented in a 0.18-/spl mu/m CMOS process.
TL;DR: In this paper, the performance of large-band Fabry-Perot (FP) filters is investigated through numerical simulations and experimental realization. And the limitations of the filters are studied theoretically to determine the impact of the chirped fiber Bragg grating (FBG) imperfections on spectral variations of the free spectral range (FSR), finesse, transmission loss, and polarization dependent loss (PDL).
Abstract: The performance of large-band Fabry-Perot (FP) filters is investigated through numerical simulations and experimental realization. The limitations of the filters are studied theoretically to determine the impact of the chirped fiber Bragg grating (FBG) imperfections on spectral variations of the free spectral range (FSR), finesse, transmission loss, and polarization dependent loss (PDL). All-fiber FP devices are realized experimentally with finesse reaching 240 and covering a spectral band of 26 nm. For finesse up to 80, the filters present acceptable performance in terms of spectral variations of FSR (/spl plusmn/3%), finesse, attenuation (/spl plusmn/0.5 dB), PDL (<0.2 dB), and insertion loss (<3 dB).
TL;DR: In this article, a compact and broad-band integrated transition between laminated waveguide in a multilayer low-temperature co-fired ceramic (LTCC) substrate and standard air-filled rectangular waveguide is presented.
Abstract: In this paper, a compact and broad-band integrated transition between laminated waveguide in a multilayer low-temperature co-fired ceramic (LTCC) substrate and standard air-filled rectangular waveguide is presented. A parallel inter-coupled two-pole filter equivalent circuit is employed to interpret the working mechanism of the transition and to predict the performance. A Ka-band prototype of the proposed broad-band transition is designed and fabricated in an LTCC substrate. The simulated and measured results of the prototyped transition show good agreement. It has been demonstrated, through the experimental results of the Ka-band prototype that the proposed transition configuration gives an effective bandwidth of over 8% with -15-dB return loss and average -0.4-dB insertion loss over the bandwidth at the Ka frequency band.
08 Jun 2003
TL;DR: In this paper, a low insertion loss (1.5dB) tunable two-pole bandpass radio frequency filter with a tuning range of one octave (812-1752 MHz) was presented.
Abstract: We demonstrate a low insertion loss (1.5dB) tunable two-pole bandpass radio frequency filter with a tuning range of one octave (812-1752 MHz). It is also tunable in band width, with 3dB-bandwidths of 7 to 42% being achieved. The circuit used consists of two fixed high quality factor toroidal inductors mounted on a printed circuit board next to a fused-quartz substrate on which were fabricated the MEMS (Micro-Electro-Mechanical System) capacitance switches. Five arrays of MEMS elements, with a total of 34 MEMS bridges, are used on this chip. Each array is independently addressable in a four-bit scheme to permit well matched, independent tuning of the center frequency and bandwidth.
TL;DR: In this article, the out-band transmission zero of the multilayer low-temperature co-fired ceramic bandpass filter is studied, where the source-load coupling capacitor incorporation with cross-coupling grounding inductors can generate three transmission zero.
Abstract: The out-band transmission zeros of the multilayer low-temperature co-fired ceramic bandpass filter are studied. The design target of this filter, with passband between 2.3-2.65 GHz (the true application is 2.4-2.483 GHz), is to reject the local oscillator and image signals and, in the mean time, to suppress the harmonic frequency. This filter is a modified three-pole combline filter, which can easily achieve a high rejection rate and low insertion loss. The source-load coupling capacitor incorporation with cross-coupling grounding inductors can generate three transmission zeros. By properly adjusting the inductance values of the inductors between three resonators and ground the transmission zero can easily be manipulated at a high-side skirt to suppress the harmonic frequency. The measured results match well with the electromagnetic simulation that provides evidence for the feasibility of the proposed design.
TL;DR: In this article, a 238/spl times/238 beam-steering optical cross-connector constructed using surface micromachined mirrors is described. But the performance of the beamforming was not evaluated.
Abstract: This letter describes a 238/spl times/238 beam-steering optical cross connect constructed using surface micromachined mirrors. Its innovative optical configuration resulted in superior optical performance, achieving a mean fiber-to-fiber insertion loss of 1.33 dB and a maximum insertion loss for all 56 644 connections of 2 dB.