Showing papers on "Insertion loss published in 2000"
TL;DR: In this article, the LC series resonance of the shunt switch was used to tune two and four-bridge "cross" switches from 10 to 40 GHz with an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a downstate isolation of 45-50 dB with only 1.5 pF of downstate capacitance.
Abstract: For pt.1 see ibid., vol.48, no.6, p.1045-1052 (2000). In this paper, the second of two parts, the equivalent RLC model of the shunt switch is used in the design of tuned two- and four-bridge "cross" switches from 10 to 40 GHz. The cross switch attained an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a down-state isolation of 45-50 dB with only 1.5 pF of down-state capacitance (C/sub d/). Also, an X-band microelectromechanical system (MEMS) switch with an insertion loss of less than 0.2 dB and an isolation of 35 dB is presented. This is done by inductively tuning the LC series resonance of the shunt switch. The MEMS bridge height is 1.5-2.5 /spl mu/m, resulting in a pull-down voltage of 15-25 V. Application areas are in low-loss high-isolation communication and radar.
320 citations
TL;DR: In this paper, a monolithic Ka-band phase shifter circuit that employs voltage tunable BaSrTiO/sub 3/ (BST) parallel plate capacitors is presented.
Abstract: Monolithic Ka-band phase shifter circuit that employs voltage tunable BaSrTiO/sub 3/ (BST) parallel plate capacitors is presented here. The circuit is capable of continuous 0/spl deg/-157/spl deg/ phase shift at 30 GHz with an insertion loss of only 5.8 dB and return loss better than 12 dB. In addition to promising loss performance (27.1/spl deg//dB) at 30 GHz, the circuit reported here has several advantages over previously reported BST phase shifters such as moderate control voltages (20 V), room temperature operation, and compatibility with monolithic fabrication techniques.
203 citations
TL;DR: In this article, a very low insertion loss silica-based arrayed-waveguide grating (AWG) achieved using a novel structure, which has vertically tapered waveguides between arrays to reduce the slab-to-arrayed waveguide transition loss.
Abstract: We propose and demonstrate a very low insertion loss silica-based arrayed-waveguide grating (AWG) achieved using a novel structure, which has vertically tapered waveguides between arrayed-waveguides to reduce the slab-to-arrayed-waveguide transition loss. A spot-size converter is also incorporated in the AWG to reduce the fiber-to-waveguide coupling loss. The structure can be formed by a process involving the conventional photolithography and reactive ion etching. The structure provided a loss reduction of 1.5 dB. Moreover, we have successfully obtained a minimum insertion loss of 0.75 dB with a crosstalk of -40 dB and polarization-independent operation.
151 citations
TL;DR: In this paper, the design, assembly, and performance of a 1/spl times/8 free-space switch demonstrator using reconfigurable holograms are reported, which operates at 1.55 /spl mu/m wavelength and has a designed optical bandwidth of >60 nm.
Abstract: The design, assembly, and performance of a prototype 1/spl times/8 free-space switch demonstrator using reconfigurable holograms are reported. Central to the switch fabric is a ferroelectric liquid crystal (FLC) on silicon spatial light modulator (SLM) deposited with a 540/spl times/1 array of highly reflective and planar mirror strips. The input and output ports of the switch are fabricated as a linear array of silica planar waveguides connected to single-mode fibers, and the holographic beam-steerer operates without the need for adjustment or dynamic alignment. The waveguide array and the single Fourier transform lens for the 2f holographic replay system are housed in an opto-mechanical mount to provide stability. The switch operates at 1.55 /spl mu/m wavelength and has a designed optical bandwidth of >60 nm. The first measured insertion loss and crosstalk figures are 16.9 dB and -19.1 dB, respectively. Improvements in SLM performance, the use of new addressing schemes and the introduction of better alignment techniques are expected to improve these figures considerably. The preliminary performance of a 3/spl times/3 optical crossconnect is also presented to show that this technology is scalable to N/spl times/N switching fabrics.
147 citations
11 Jun 2000
TL;DR: In this article, a push-pull type microwave switch is proposed, which utilizes torsion springs and leverage for lowvoltage operation, and the actuation voltage is /spl sim/5 V.
Abstract: In this paper, a push-pull type microwave switch is proposed, which utilizes torsion springs and leverage for low-voltage operation. The switching operation up to 4 GHz is demonstrated. The actuation voltage is /spl sim/5 V. The insertion loss of /spl sim/1 dB and the isolation as high as /spl sim/40 dB at 1 GHz are achieved by the push-pull operation.
138 citations
TL;DR: In this article, the authors proposed techniques for minimizing optical transmission losses in polySi strip waveguides, which showed an optical transmission loss of 15 dB/cm at λ=1.32 µm and 1.55 µm, which is a communication wavelength of choice in optical fibers.
Abstract: Signal propagation delays dominate over gate delays in the ever-shrinking ultra large scale integrated (ULSI) circuits. Consequently, silicon-based monolithic optoelectronic circuits (SMOE) with their light speed signal propagation can provide unique advantages for future generations of microprocessors. For such SMOE circuits, we need optical interconnects compatible with silicon technology. Strip waveguides consisting of polycrystalline silicon (polySi) clad with SiO2 offer excellent optical confinement and ease of fabrication that are ideal for such interconnect applications. One major challenge with using this material system, however, is its insertion loss. In this paper we provide techniques for minimizing optical transmission losses in polySi strip waveguides. Our previous work using polySi strip waveguides, showed an optical transmission loss of 15 dB/cm at λ=1.55 µm, which is a communication wavelength of choice in optical fibers because it represents an absorption minimum. Similar measurements in crystalline silicon strip waveguides1 yielded transmission losses of less than 1 dB/cm. Hitherto, in decreasing loss from 77 dB/cm to 15 dB/cm, we had minimized loss from surface scattering by improving the film surface morphology, and decreased bulk absorption with hydrogen passivation. In this paper we report a further reduction in the residual bulk loss from 15 dB/cm to 9 dB/cm. By experimenting with different waveguide core dimensions, we find that the contribution of bulk loss towards net transmission loss decreases with waveguide core thickness. Additionally, high temperature treatment provides strain relief in the polySi, decreasing transmission loss. Annealing in an oxygen ambient is not recommended because it always increases transmission loss. Hydrogen passivation improves transmission, attributable to passivation of light-absorbing dangling bond defect sites present at polySi grain boundaries. Together, these methods have resulted in the lowest measured loss value of 9 dB/cm at λ=1.55 µm. Since integrated SiGe and Ge photodetectors are more efficient at shorter wavelengths like λ=1.32 µm, transmission loss is also measured at λ=1.32 µm. Losses at the two wavelengths (1.32 µm and 1.55 µm) are similar when defects and stress in the waveguides are minimized.
109 citations
TL;DR: In this article, the design and performance of a compact K-band 5-bit phase-shifter monolithic microwave integrated circuit (MMIC) is presented, and extensive electromagnetic simulation and compact circuit design techniques are employed to yield an MMIC with a 1.693 mm/spl times/0.750 mm (1.27 mm/sup 2/) die size.
Abstract: The design and performance of a compact K-band 5-bit phase-shifter monolithic microwave integrated circuit (MMIC) is presented. Extensive electromagnetic simulation and compact circuit design techniques were employed to yield an MMIC with a 1.693 mm/spl times/0.750 mm (1.27 mm/sup 2/) die size. Measured performance of the phase shifter at 19 GHz demonstrates 5 dB/spl plusmn/0.6 dB insertion loss and 30 r.m.s. phase error.
102 citations
TL;DR: In this paper, a 3-bit K-band distributed phase shifter circuit that employs microelectromechanical systems (MEMS) capacitive switches is presented. And the measured results demonstrate an average 1.7 dB insertion loss at 26 GHz with return loss better than -7 dB.
Abstract: In this work, we present a 3-bit K-band distributed phase shifter circuit that employs microelectromechanical systems (MEMS) capacitive switches. The measured results demonstrate an average 1.7 dB insertion loss at 26 GHz with return loss better than -7 dB. Insertion phase shifts of all switching states are measured and show phase error less than 8.50 for all states. The low loss K-band 3-bit phase shifter demonstrated here can potentially be extended to more-bit-controlled phase shifter applications.
100 citations
21 Aug 2000
TL;DR: In this article, the MARS (mechanical anti-reflection switch) devices have been discussed, in which the membranes in the first devices have the same thickness and refractive index as an antireflection coating.
Abstract: We discuss our so-called MARS (mechanical anti-reflection switch) devices, in which the membranes in the first devices have the same thickness and refractive index as an anti-reflection coating. By varying the air gap between odd and even multiples of /spl lambda//4 the reflectivity goes from high to near zero. This can be easily understood since if the air gap is zero it is of anti-reflecting and if it is /spl lambda//4 a high reflector mirror stack is formed, and since in any optical stack the reflectivity at the center wavelength is independent of additions of /spl lambda//2 to any layer. Six devices are described that only require variations on the layer structure of this simple mechanical structure, including changes in refractive index and thickness and additional layers. These are the simple data modulator requiring only on and off states, and the design methodology for trading insertion loss for wavelength range, a linear response device for producing harmonic signals, an attenuator requiring variable reflectivity that is independent of wavelength, a multi-electrode wavelength power equalizer, a gain slope compensator that has variable spectral tilt without attenuation changes, and a display design for operation over the entire visible spectrum.
99 citations
TL;DR: In this article, a micromachined microwave switch on a semi-insulating GaAs substrate using a microactuator and a coplanar waveguide (CPW) using electrostatic actuation as the switching mechanism is presented.
Abstract: This work fabricates a novel type of micromachined microwave switch on a semi-insulating GaAs substrate using a microactuator and a coplanar waveguide (CPW) using electrostatic actuation as the switching mechanism. The microactuator uses several continuously-bent cantilevers connected in series. A cantilever with two sections, a straight-beam section and a curved-beam section, forms the basic unit of the microactuator. The straight-beam section is made of an aluminum (Al) layer, 0.5 μm thick. The curved-beam section is made of an Al layer of the same thickness, combined with a 0.1-μm layer of chromium (Cr) film. This section is initially curled due to the different residual stress of Al and Cr. The low temperature (250°C) process ensures that the switch is capable of monolithic integration with microwave and millimeter wave integrated circuits (MMIC). When no dc potential is applied, the actuator is curled far from the signal line of the CPW, and therefore the insertion loss at this `on' state is only 0.2 dB at 10 GHz. Because the metal microactuator is far from the signal line of the CPW at this `on' state, the microwave propagation is hardly disturbed by the microactuator. When an applied electrostatic force pulls the actuator tip down into contact with the signal line of the CPW, it creates a large capacitance between the actuator and the CPW. The isolation at this `off' state is −17 dB at 10 GHz. Maintaining the actuator in the `off' state requires only a very low actuation voltage of 26 V. Once the dc potential is removed, the residual stress of the actuator structure pulls it to the up position. The microactuator moving back and forth between these two switching states, acts like the movement of a frog's tongue. This switch has excellent performance at the wide-band RF frequencies used in transmit/receive modules of wireless communication. This study measured the critical corrupt (activating) voltage and recovery voltage of the microactuator. The 10-ms switching time of this switch is slower than the switching time of solid-state switches.
98 citations
TL;DR: In this article, a one-bit low-loss K/K/sub a/-band phase shifter circuit that employs microelectromechanical systems capacitors is presented.
Abstract: This letter presents a one-bit low-loss K/K/sub a/-band phase shifter circuit that employs microelectromechanical systems (MEMS) capacitors. The measured results demonstrate a delay line with a 180/spl deg/ phase shift/1.l7 dB loss phase shift at 25 GHz, 270/spl deg/ phase shift/1.69 dB loss at 35 GHz, and a return loss better than 11 dB over a 0-35-GHz band. The state-of-the-art insertion loss performance, 154/spl deg//dB at 25 GHz and 160/spl deg//dB at 35 GHz, demonstrates the potential for the implementation of a very low-loss multibit digital MEMS phase shifter.
TL;DR: In this article, a free-space optical fiber crossconnect that uses a pair of micromirror arrays to redirect optical beams from an input-fiber array to an output array is described.
Abstract: This letter describes a free-space optical fiber cross-connect that uses a pair of micromirror arrays to redirect optical beams from an input-fiber array to an output array. This confocal switch architecture is well suited for simultaneous switching of multiple wavelength channels. We show that confocal switches with low insertion loss, low crosstalk, and large port counts can be implemented with surface-micromachined mirror arrays, and we demonstrate a 2/spl times/2 single-mode (1550 nm) switch configuration with insertion loss of -4.2 dB and crosstalk of -50.5 dB. Our micromirror design has sufficient size and angular deflection for scaling to 32/spl times/32 ports.
TL;DR: In this paper, a simple comb filter based on a Sagnac interferometer with a fiber Bragg grating asymmetrically located in its fiber loop was proposed for erbium-doped fiber ring laser.
Abstract: We introduce a novel simple comb filter, which is based on a Sagnac interferometer with a fiber Bragg grating asymmetrically located in its fiber loop. The filter has advantages of simple design and easy fabrication, low insertion loss and low cost. Two filters with triple bandpasses and dual bandpasses, respectively, were fabricated and applied to an erbium-doped fiber ring laser. Stable triple-wavelength and dual-wavelength laser operations have been demonstrated.
TL;DR: In this paper, a 2×2 silica-based optical waveguide switch that is based on a thermocapillarity effect was designed to provide a cross/bar function through a single element, and measured reflection losses in the reflection walls on both sides of the slit were consistent.
Abstract: We have designed a structure for a 2×2 silica-based optical waveguide switch that is based on a thermocapillarity effect. This switch can use the reflection walls on both sides of the slit, because the Goos–Hanchen shift effect was taken into account when the structure of the waveguides and the slit was designed. This switch can provide a cross/bar function through a single element, and the measured reflection losses in the reflection walls on both sides of the slit were consistent. The loss was comparable to the insertion loss of a Mach–Zender-interferometer-type thermo-optic switch.
TL;DR: In this paper, the insertion loss and Q-factors of the filters vary with the product of the thickness and conductivity of the metal film for lead and gold films, even in cases when the thickness is several skin depths at the center frequency.
Abstract: In this paper, we present terahertz bandpass filters composed of resonant arrays of crossed slots in lossy metal films deposited on dielectric membranes. The filters exhibit insertion loss as low as 1.9 dB at room temperature and 1.2 dB at 77 K at a center frequency of 2.2 THz. It is found that the dielectric substrate introduces a downward shift in frequency not predicted by standard mean dielectric-constant approximations. This shift is proportional to the permittivity and thickness of the substrate, and is accurately modeled for polyester, fused quartz and silicon substrates using a finite-difference time-domain (FDTD) model. It is also found that the insertion loss and Q-factors of the filters vary with the product of the thickness and conductivity of the metal film for lead and gold films, even in cases when the thickness is several skin depths at the center frequency. The FDTD theory presented here accounts for some of the conductor losses.
TL;DR: The latest experimental results of novel HTS preselect bandpass filters, including those encapsulated with a low-noise amplifier in an RF module are presented, showing very promising performance.
Abstract: The low-loss and high-selective high-temperature superconducting (HTS) bandpass filters can enhance performance of mobile communications systems. In this paper, we summarize a recent progress of novel HTS preselect bandpass filters that have been developed for a European research project. The objective of the project is to construct an HTS-based transceiver for mast-mounted DCS1800 base stations. The HTS preselect receive filters have been designed to have a quasi-elliptic function response in order to provide low insertion loss and very steep rolloff at the filter band edges. The filters cover a 15-MHz sub-band of a receive band, which ranges from 1710 to 1785 MHz. The filters have been fabricated using double-sided YBCO thin films on 03-mm-thick MgO or 0.5-mm-thick LAO substrates. The latest experimental results of the filters, including those encapsulated with a low-noise amplifier in an RF module are presented, showing very promising performance. The issues associated with asymmetric frequency response are investigated to improve the filter performance.
TL;DR: In this paper, the authors examined the performance of the optical signal whose chirp is controlled by utilizing phase modulation in semiconductor optical amplifier (SOA) with both simulations and experiments.
Abstract: We examine the fiber transmission performance of the optical signal whose chirp is controlled by utilizing phase modulation in semiconductor optical amplifier (SOA) with both simulations and experiments. This chirp control technique converts a positive chirp created by electroabsorption (EA) modulator into negative chirp, which reduces the waveform degradation due to the chromatic dispersion in transmission over standard single-mode fiber (SMF). It also provides an optical gain that is sufficient to compensate the insertion loss of the EA modulator. We investigate how the chirp control is affected by the input power to the SOA and the carrier lifetime of the SOA. As the SOA input power increases, the negative chirp becomes large, while the waveform is largely distorted due to gain saturation. However, the waveform distortion at high SOA input powers can be shaped by using a frequency discriminator. The acceleration of the carrier lifetime also reduces the waveform distortion due to gain saturation. We demonstrate that the chirp control technique is effective even for a high bit rate optical signal up to 10 Gb/s, when the carrier lifetime is expedited by optical pumping.
TL;DR: In this article, a distributed coplanar-waveguide (CPW) phase shifter with high capacitance-ratio varactors was developed for X-band operation.
Abstract: A wideband distributed coplanar-waveguide (CPW) phase shifter has been developed for X-band operation. The design is based on the distributed MEMS transmission line (DMTL) loaded with high capacitance-ratio varactors. The varactors are fabricated using a series combination of MEMS bridges and fixed-value MIM capacitors. A high-capacitance ratio varactor (1.5-2.5) results in a large loading on the CPW line and therefore a large phase shift. A distributed phase shifter was fabricated on a 500 /spl mu/m quartz substrate, and achieved a true-time delay operation from 1 to 10 GHz with a reflection coefficient less than /spl sim/15 dB, and 1800/dB of insertion loss at 8-10 GHz. It is possible with this design to cascade the DMTL to result in 2- and 3-bit phase shifters with excellent wideband performance at X-band frequencies.
TL;DR: In this article, a 2-axis tilting micromirror was designed and fabricated in a 2 structural + 1 interconnect layer polysilicon process, which is capable of large, continuous, controlled DC tilt in any direction at moderate actuation voltages.
Abstract: Electrostatically actuated, 500micrometers diameter, Si surface micromachined 2-axis tilting micromirrors were designed and fabricated in a 2 structural + 1 interconnect layer polysilicon process. The mirrors are capable of large, continuous, controlled, DC tilt in any direction at moderate actuation voltages. The lowest-mode resonance frequency is sufficiently high to decouple from the ambient vibration noise and allow setting times of less than a few milliseconds. The Au- coated reflectors, suspended in gimbal mounts via torsional springs and bearings, are tilted by applying voltage to four electrically independent sets of fixed electrodes on the substrate. The electrodes and the springs are designed to optimize actuation voltages, resonance frequencies and the deflection range. To achieve the range, the mounts are lifted and fixed fifty microns above the substrate surface during the release process by a self-assembly mechanism powered by tailored residual stress in a separate metalization layer. Square arrays with 1 mm pitch containing independently addressable identical 16, 64 and 256 mirrors were fabricated and hermetically packaged. Based on these devices, fully functional, bitrate and wavelength independent, single stage, low insertion loss, single mode fiber optical crossconnect system are built.
23 Jan 2000
TL;DR: In this article, Strontium Titanate Oxide (SrTiO/sub 3/) with high dielectric constant is investigated for high switching on/off ratio and on capacitance as a dielectoric layer of a micromechanical capacitive switch.
Abstract: RF microswitches are newly designed and fabricated with various structural geometry of transmission line, hinge, and movable plate formed by using electroplating techniques, low temperature processes, and dry releasing techniques. In particular, Strontium Titanate Oxide (SrTiO/sub 3/) with high dielectric constant is investigated for high switching on/off ratio and on capacitance as a dielectric layer of a micromechanical capacitive switch. Achieved lowest actuation voltage of the fabricated switches is 8 volts. The fabricated switch has low insertion loss of 0.08 dB at 10 GHz, isolation of 42 dB at 5 GHz, on/off ratio of 600, and on capacitance of 50 pF, respectively. These switches also have high current carry capability due to the use of electroplated Au or Cux.
TL;DR: In this article, a low-loss flat-top interleave filter with 200 GHz channel spacing is fabricated using planar lightwave circuit (PLC) technology, which has a two-stage lattice structure and demonstrates an insertion loss of 0.9 dB and a 1 dB bandwidth of 140 GHz.
Abstract: A low-loss flat-top interleave filter with 200 GHz channel spacing is fabricated using planar lightwave circuit (PLC) technology. The interleaver has a two-stage lattice structure and demonstrates an insertion loss of 0.9 dB and a 1 dB bandwidth of 140 GHz.
NEC1
TL;DR: In this paper, a Ka-band monolithic phase shifter utilizing nonresonant FET switches is described, which shows broad-band on/off characteristics up to 60 GHz without using inductors.
Abstract: This paper describes design consideration and performance of a Ka-band monolithic phase shifter utilizing nonresonant FET switches. The switches show broad-band on/off characteristics up to 60 GHz without using inductors; thus, robust circuit design is possible for a switched-line phase shifter. To determine circuit topology, we introduce a schematic design approach. As a result, desired phase shift as well as good matching characteristics can be realized. The developed 4-bit monolithic phase shifter demonstrates an overall phase deviation less than 5/spl deg/ rms and an insertion loss variation less than 0.65 dB rms from 33 to 35 GHz. For all 16 states, the insertion loss is measured to be 13.1/spl plusmn/1.1 dB and the VSWR is less than 1.6. The chip size of the monolithic phase shifter is 2.5 mm/spl times/2.2 mm.
07 Mar 2000
TL;DR: In this article, the authors proposed a 32/spl times/32-size switch matrices with transmission losses of 0.07 dB per crosspoint, crosstalk of /spl sim/70 dB per point, and switching times of 1 msec.
Abstract: Optical cross-connect switch matrices have demonstrated transmission losses of 0.07 dB per crosspoint, crosstalk of /spl sim/70 dB per crosspoint and switching times of 1 msec. We now have the technology to produce 32/spl times/32-size matrices.
TL;DR: In this paper, a new time-delay phase shifter using a piezoelectric transducer (PET) on a microstrip line with computational and experimental results is presented.
Abstract: This paper presents a new time-delay phase shifter using a piezoelectric transducer (PET) on a microstrip line with computational and experimental results. Dielectric perturbation changes the line capacitance and propagation constant of the microstrip line. The phase of the microstrip line is varied, but insertion loss is not much affected. A maximum phase shift of 460/spl deg/ with respect to the unperturbed condition has been achieved with an increased insertion loss of less than 2 dB and a total loss of less than 4 dB up to 40 GHz, using the dielectric perturbation controlled by PET. The proposed phase shifter should have many applications in antenna beam steering and in other microwave and millimeter-wave circuits.
TL;DR: In this article, a 2-bit distributed coplanar-waveguide (CPW) phase shifter was developed for X-band operation based on distributed MEMS transmission line (DMTL) loaded with MEMS bridges and MIM capacitors.
Abstract: A wideband distributed coplanar-waveguide (CPW) phase shifter has been developed for X-band operation The design is based on the distributed MEMS transmission line (DMTL) loaded with MEMS bridges and MIM capacitors A 2-bit distributed phase shifter was fabricated on a 500-/spl mu/m quartz substrate, and achieved a true-time delay operation from 1 to 20 GHz with a reflection coefficient less than -11 dB from 2 to 20 GHz and above Insertion loss is dominated by a low-Q MIM capacitor (14 at 10 GHz) and the effect of this Q is shown, Increasing the MIM capacitor Q will result in an excellent 2-bit phase shifter with wideband performance at X-band frequencies
TL;DR: In this article, a simple micromachining solution is used to cancel the parasitic modes triggered by the transition in the grounded coplanar waveguide feed line, which results in an insertion loss of 0.3 dB and a return loss better than -18 dB from 75 to 110 GHz.
Abstract: Mode conversion at the transition between grounded coplanar waveguide (GCPW) and microstrip line is demonstrated. Experimental results show the effect of overmoding in a conductor-backed coplanar waveguide on the transition behavior. A simple micromachining solution is used to cancel the parasitic modes triggered by the transition in the GCPW feed line. This results in an insertion loss of 0.3 dB and a return loss better than -18 dB from 75 to 110 GHz. The transition can prove very useful for millimeter-wave packaging and interconnects.
TL;DR: In this article, a dual-mode elliptic-function bandpass filter with one coupling gap structure was proposed, which has a 4.7% bandwidth at 1.805 GHz with 1.73 dB insertion loss.
Abstract: A novel microwave dual-mode elliptic-function bandpass filter with one coupling gap structure is proposed. This filter has a 4.7% bandwidth at 1.805 GHz with 1.73 dB insertion loss. The filter provides less field perturbation of the ring resonator than conventional filters. Without the output coupling gap between the feed line and the ring resonator, a low insertion loss has been obtained. This compact, high performance filter is useful for mobile and personal communication systems.
Patent•
25 Aug 2000TL;DR: In this paper, the insertion loss of a two-port capacitance was shown to be more than −40 dB over a range from 1 GHz to 10 GHz and no inductive resonance below a frequency of at least 1 GHz.
Abstract: A capacitor exhibits high two-port insertion loss even at frequencies as high as 10 GHz. Notably, the capacitor exhibits an insertion loss of more than −40 dB over a range from 1 GHz to 10 GHz and no inductive resonance below a frequency of at least 1 GHz.
TL;DR: In this article, the coplanar waveguide-to-coplanar stripline (CPS) transition is analyzed theoretically and experimentally in the lower frequency band, and a simple equivalent-circuit model that consists of uniform and nonuniform transmission lines is established.
Abstract: The coplanar waveguide (CPW)-to-coplanar stripline (CPS) transition is analyzed theoretically and experimentally in this paper. To characterize this transition in the lower frequency band, a simple equivalent-circuit model that consists of uniform and nonuniform transmission lines is established. The elements of this model can all be obtained by the closed-form formulas; hence, this model is suitable for computer-aided-design application. This model is then applied to design and analyze the CPW-to-CPS transitions with various structure parameters. In the higher frequency band, the partially prism-gridded finite-difference time-domain (FDTD) method is employed to take into account the bond-wire effect as well as the surface-wave leakage and space-wave radiation associated with the transition. In this study, results based on equivalent-circuit model, FDTD simulation, and measurement are compared. Good agreement among these results supports the usefulness of the proposed equivalent-circuit model and also validates the FDTD method. By using the equivalent-circuit model to optimize the transition configuration, the CPW-to-CPS transition with broad bandwidth and low insertion loss may be achieved.
Patent•
01 May 2000TL;DR: In this article, a first attenuator inputs a radiofrequency signal and outputs an output signal after controlling the inputted radio-frequency signal, and outputs it to one of a main transmission line and an auxiliary transmission line.
Abstract: A transmit power control circuit, which can control a transmit power of a transmit power control circuit through wide dynamic range and can reduce an insertion loss. A first attenuator inputs a radio-frequency signal and outputs an output signal after controlling the inputted radio-frequency signal. A selective switch inputs the output signal of the first attenuator, and outputs it to one of a main transmission line and an auxiliary transmission line. One directional coupler is provided to the main transmission line and has one and another ends respectively connected to selective switches. The selective switches are switched by a signal from a microcomputer. When the selective switch is switched to the main transmission line, one end of the directional coupler is connected to a terminator, and another end thereof is connected to a wave detector. On the contrary, when the selective switch is switched to the auxiliary transmission line, one end of the directional coupler is connected to the auxiliary transmission line, and another end thereof is connected to a terminator.