Showing papers on "Insertion loss published in 2001"

Integrated microstrip and rectangular waveguide in planar form

Abstract: Usually transitions from microstrip line to rectangular waveguide are made with three-dimensional complex mounting structures. In this paper, a new planar platform is developed in which the microstrip line and rectangular waveguide are fully integrated on the same substrate, and they are interconnected via a simple taper. Our experiments at 28 GHz show that an effective bandwidth of 12% at 20 dB return loss is obtained with an in-band insertion loss better than 0.3 dB. The new transition allows a complete integration of waveguide components on substrate with MICs and MMICs.

Single side-band modulation performance of a LiNbO 3 integrated modulator consisting of four-phase modulator waveguides

Abstract: Single side-band (SSB) technologies are especially useful in optical fiber communication systems, such as higher density wavelength multiplexing and long-haul fiber transmission due to less nonlinear optical effects, because of the reduced optical power. This letter reports on the SSB modulation performance of a LiNbO/sub 3/ integrated modulator consisting of four phase modulator waveguides. Optical SSB modulation with suppressions of main carrier (-22.6 dB) and J/sub 3/ subcarrier (-18.4 dB) of a 10-GHz single-tone signal with a driving voltage of 6.3 V/sub p-p/ was demonstrated. The total insertion loss was 10.6 dB.

A 0.5-/spl mu/m CMOS T/R switch for 900-MHz wireless applications

Abstract: A single-pole double-throw transmit/receive switch for 30-V applications has been fabricated in a 05-/spl mu/m CMOS process An analysis shows that substrate resistances and source/drain-to-body capacitances must be lowered to decrease insertion loss The switch exhibits a 07-dB insertion loss, a 17-dBm power 1-dB compression point (P/sub 1 dB/), and a 42-dB isolation at 928 MHz The low insertion loss is achieved by optimizing the transistor widths and bias voltages, by minimizing the substrate resistances, and by dc biasing the transmit and receive nodes, which decreases the capacitances while increasing the power 1-dB compression point The switch has adequate insertion loss, isolation, P/sub 1 dB/, and IP/sub 3/ for a number of 900-MHz ISM band applications requiring a moderate peak transmitter power level (/spl sim/15 dBm)

MEM relay for reconfigurable RF circuits

Abstract: We describe a microelectromechanical (MEM) relay technology for high-performance reconfigurable RF circuits. This microrelay, fabricated using surface micromachining, is a metal contact relay with electrical isolation between signal and drive lines. This relay provides excellent switching performance over a broad frequency band (insertion loss of 0.1 dB and isolation of 30 dB at 40 GHz), versatility in switch circuit configurations (microstrip and coplanar, shunt and series), and the capability for monolithic integration with high-frequency electronics. In addition, this MEM relay technology has demonstrated yields and lifetimes that are promising for RF circuit implementation.

A DC-to-40 GHz four-bit RF MEMS true-time delay network

Abstract: A monolithic true-time delay (TTD) network containing sixteen metal-to-metal contact RF microelectromechanical systems (MEMS) switches has been successfully fabricated and characterized The TTD network was designed to produce flat delay time over a dc-to-40 GHz bandwidth with full 360-degree phase control at 225-degree intervals at 108 GHz Measurements show a close match to the designed delay times for all sixteen switch states with 22 to 26 dB of insertion loss at 10 GHz The worst group delay ripple in the dc-to-30 GHz range was 3 ps, well within the single bit delay time of 58 ps

RF MEMS‐based tunable filters

Abstract: This paper overviews the application of RF MEMS switches in tunable filters as well as circuit developments for bandpass filters covering 110 MHz to 2.8 GHz. RF MEMS have several desirable features, including small size, low power requirements, and low loss. The basic operation of Raytheon's RF MEMS capacitive membrane switch is described. An overview of the technique used to integrate the switch into a variable capacitor structure with sixteen capacitance states is provided. Variable capacitor structures are used to construct multipole lumped bandpass filter designs, each with sixteen states. Finally, measured data from two representative five- and six-pole bandpass filters are presented. Characterization data demonstrates that the insertion loss for the five-pole filter using on-chip inductors was between 6.6 and 7.3 dB, and between 3.7 and 4.2 dB for the six-pole filter using off-chip inductors. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE11: 276-284, 2001.

A 2.4-GHz-band 1.8-V operation single-chip Si-CMOS T/R-MMIC front-end with a low insertion loss switch

Abstract: This paper describes the design and experimental results of a 1.8-V single-chip CMOS MMIC front-end for 2.4-GHz band short-range wireless communications, such as Bluetooth and wireless LANs. The IC consists of fundamental RF building circuits-a power amplifier (PA), a low-noise amplifier (LNA), and a transmit/receive-antenna switch (SW), including almost all on-chip matching elements. The IC was fabricated using a 0.18-/spl mu/m standard bulk CMOS technology which has no extra processing steps to enhance the RF performances. Two new circuit-design techniques are introduced in the IC in order to minimize the insertion loss of the SW and realize a higher gain for the PA and LNA despite the utilization of the standard bulk CMOS technology. The first is the derivation of an optimum gate width of the SW to minimize the insertion loss based on small-signal equivalent circuit analysis. The other is the revelation of the advantages of interdigitated capacitors (IDCs) over conventional polysilicon to polysilicon capacitors and the successful use of the IDCs in the LNA and PA. The IC achieves the following sufficient characteristics for practical wireless terminals at 2.1 GHz and 1.8 V: a 5-dBm transmit power at a -1-dB gain compression, a 19-dB gain, an 18-mA current for the PA, a 1.5-dB insertion loss, more than 24-dB isolation, an 11-dBm power handling capability for the SW, a 7.5-dB gain, a 4.5-dB noise figure, and an 8-mA current for the LNA.

Monolithically integrated micromachined RF MEMS capacitive switches

Abstract: RF MEMS switches 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 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 V. 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.

Miniature low-loss CPW periodic structures for filter applications

Abstract: Several novel periodic structures for coplanar waveguides are presented. The proposed structures exhibit low insertion loss in the passband, simple fabrication, and slow-wave characteristics. These structures are applied to realize miniature low-pass filters one-tenth the size of conventional filters, with spurious-free response and deep attenuation levels using only three cells.

Low loss and high extinction ratio strictly nonblocking 16/spl times/16 thermooptic matrix switch on 6-in wafer using silica-based planar lightwave circuit technology

Abstract: We describe a silica-based 16/spl times/16 strictly nonblocking thermooptic matrix switch with a low loss and a high extinction ratio. This matrix switch, which employs a double Mach-Zehnder interferometer (MZI) switching unit and a matrix arrangement to reduce the total waveguide length, is fabricated with 0.75% refractive index difference waveguides on a 6-in silicon wafer using silica-based planar lightwave circuit (PLC) technology. We obtained an average insertion loss of 6.6 dB and an average extinction ratio of 53 dB in the worst polarization case. The operating wavelength bandwidth completely covers the gain band of practical erbium-doped fiber amplifiers (EDFAs). The total power consumption needed for operation is reduced to 17 W by employing a phase-trimming technique which eliminates the phase-error in the interferometer switching unit.

Wide-band low-loss high-isolation microstrip periodic-stub diplexer for multiple-frequency applications

Abstract: This paper introduces a three-port microstrip multifrequency diplexer used in a phased-array transceiver system that employs band-stop filters with open-circuited stubs for band selection and separation. The diplexer is designed to take 10, 12, 19, and 21 GHz into port 1 and to separate 10 and 19 GHz to port 2 and 12 and 21 GHz to part 3 with minimal dispersion. The insertion loss for each frequency varies from 0.4 to 3.4 db and the return loss is better than 10 dB. The isolation between channels at the four frequencies is greater than 50 dB. Each passband created between adjacent stopbands has a bandwidth over 1 GHz. The microstrip diplexer is designed using periodic stubs that collectively have the advantages of low insertion loss, high isolation and rejection, wide-band performance on each channel, and easy fabrication. This type of diplexer has many applications in multifrequency transceivers for communication systems.

MEMS based variable optical attenuator (MBVOA)

Abstract: The present invention discloses an optimized optical attenuator device. It includes the design of resonator formed by two identical mirrors, which are made by MEMS process. The structure realizes the minimum insertion loss. The two membranes are chosen to be with high reflection rate. Multiple layer or metal layer or mixture of them can produce membrane of high reflection rate. High reflection rate causes low tuning voltage for one certain attenuation range. To reduce the manufacture error and the cost, the two identical membranes can be formed by bonding two MEMS cells fabricated in the same process face to face. To further reduce the insertion loss, the input mode should match the residual basic mode in the resonator. The basic residual mode is the only one surviving in the resonator. A design of the resonator will guarantee this happen. Ripple is a key specification for present optical component. To achieve very low ripple device, all the interfaces of the MEMS device should be coated with anti-reflection coating. The lower the reflection rate is, the lower the ripple is. Charging will cause the control voltage craze while using the attenuator device. To eliminate the charging effect, the electrode should be attached to the conductive face to face layers during the tuning process, which means between the two electrodes, positive and negative, there should be no dielectric material to trap the charges. However, one or two very thin dielectric layers between the two conductive layer electrodes can improve the electric breakdown voltage. The dielectric material and the thickness are selected without generating severe charging effect, while the safety of MEMS device can be guaranteed. Finally, the device is controlled by a smart control system with the temperature and wavelength compensation functionality. The control system makes the device stable and will keep the attenuation fixed regardless the temperature or wavelength changing. A device should have communication interface with system.

1296-port MEMS transparent optical crossconnect with 2.07 petabit/s switch capacity

Abstract: A 1296-port MEMS transparent optical crossconnect with 5.1dB/spl plusmn/1.1dB insertion loss at 1550 nm is reported. Measured worst-case optical crosstalk in a fabric was n38 dB and nominal switching rise/fall times were 5 ms. A 2.07 petabit/s switch capacity was verified upon cross-connecting a forty-channel by 40 Gb/s DWDM data stream through a prototype fabric.

Distributed MEMS transmission lines for tunable filter applications

Abstract: This paper describes the design and fabrication of a distributed MEMS () transmission line DMTL , used to realize a transmission-line with a voltage-variable electrical length for microwave circuits. The DMTL is a coplanar waveguide periodically loaded with continuously-variable MEMS capacitors. A tunable bandpass filter was de- signed and fabricated on 700 m thick glass substrates using three capacitively coupled DMTL sections as variable shunt resonators. The measured results demonstrate a 3.8% tuning range at 20 GHz with 3.6 dB minimum insertion loss. Issues for future improvement are discussed. 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 254260, 2001.

Sol–gel derived grain oriented barium strontium titanate thin films for phase shifter applications

Abstract: In the present work process methodology was optimized to synthesize oriented barium strontium titanate (BST) (50/50) and (60/40) thin films on strontium titanate (100) and lanthanum aluminate (LAO) (100) substrates by using the chemical solution deposition technique. These films were characterized in terms of their phase formation behavior and structural growth characteristics using x-ray diffraction and atomic force microscopy. A tentative mechanism of the epitaxial growth has been proposed. Films were also characterized in terms of their dielectric properties. The high tunability and low dielectric loss of these films make them attractive for fabricating tunable dielectric devices. Accordingly, we have fabricated eight element coupled microstrip phase shifters and tested them in terms of their degree of phase shift and insertion loss characteristics. An insertion loss of 8.435 dB, phase shift in the order of 320° (2.6–14.5 V/μm) and κ factor (phase shift/dB of loss) of about 38.0°/dB was achieved in BST (60/40) films deposited on LAO (100) substrate which is comparable to the films grown by other film deposition techniques reported in the literature. The microstructure of the sol–gel derived films show surface porosity which may be responsible for the low dielectric strength of these films. Presently, we are studying the sintering mechanism and kinetics of these films in order to improve the density which is believed to further improve the phase shift and lower insertion loss to result in an improved tunability.

Integrated self-biased hexaferrite microstrip circulators for millimeter-wavelength applications

Abstract: Planar microstrip Y-junction circulators have been fabricated from metallized 130-/spl mu/m-thick self-biased strontium hexaferrite ceramic die, and then bonded onto silicon die to yield integrated circulator circuits. The impedance matching networks needed to transform the low-impedance circulator outputs were deployed on low-loss alumina or glass dielectrics to minimize circuit losses. These magnetically self-biased circulators show a normalized isolation and insertion loss of 33 and 2.8 dB, respectively, and a 1% bandwidth for an isolation of 20 dB. Application of small (H<1.5 kOe) magnetic bias fields improved the isolation and insertion loss values to 50 and 1.6 dB, respectively. This design may form the basis for future monolithic millimeter-wave integrated circulator circuits that do not require magnets.

Design and characterization of compact single-section passive polarization rotator

Abstract: In this paper an improved design for a short and low-loss polarization rotator is proposed, consisting of a single-section asymmetrical waveguide butt-coupled between two standard rib waveguides. At a wavelength of 1.55 /spl mu/m, nearly 100% polarization conversion ratio is obtained, with a relatively short (320 /spl mu/m) device length and an extremely low 0.5 dB total insertion loss. The simulation results are obtained using the full vectorial finite-element-based beam propagation, the junction analysis, and the modal solution approaches.

Super self-aligned GaAs RF switch IC with 0.25 dB extremely low insertion loss for mobile communication systems

Abstract: An extremely low loss switch IC has been implemented by using a 015 /spl mu/m-gate super self-aligned FET with reduced drain/source area Both off-state-capacitance and the specific on-resistance of the implemented FET have been dramatically reduced by the novel device structure The experimentally fabricated switch IC showed the low insertion loss of 025 dB at an added power of 35 dBm at a frequency of 09 GHz, which is the lowest value ever reported

Epitaxially grown GaN thin-film SAW filter with high velocity and low insertion loss

Abstract: This study proposes GaN thin film as a piezoelectric material for SAW (surface acoustic wave) filters. Highly piezoelectric GaN film with a good surface morphology (RMS roughness =0.7 nm) was obtained on a 2-in (0001)-oriented sapphire substrate by MOCVD growth. The fabricated GaN SAW filter exhibited a very high velocity of 5803 m/s and relatively low insertion loss of -7.7 dB, The attenuation of the center frequency was about 22 dB smaller than those at the tops of the first sidelobes. When the wavelength of the IDT electrode was 60 /spl mu/m (/spl lambda//4=15 /spl mu/m), the center frequency was measured at 96.6 MHz, thereby facilitating a /spl sim/GHz operation when the IDT geometry is designed on a 1 /spl mu/m scale. The calculated electromechanical coupling factor (K/sup 2/) was about 4.3/spl plusmn/0.3% which is larger than those obtained from other thin film piezoelectric materials and allows the realization of wider filter fractional bandwidths. TCF (temperature coefficient of frequency) was measured as low as -18.3 ppm//spl deg/C in the range from -25 to 50/spl deg/C. These superior characteristics demonstrate that epitaxially grown GaN thin film can be successfully used for high performance SAW filters.

A wideband coplanar stripline to microstrip transition

Abstract: A wideband coplanar stripline (CPS)-to-microstrip line was developed. The transition has a simple structure for the ease of fabrication with low cost. The measured performance of two back-to-back transitions exhibits an insertion loss of less than 3 dB and a return loss of better than 10 dB over a bandwidth from 1.3 GHz to 13.3 GHz (1:10.2). For narrower bandwidth, an insertion loss of less than 1 dB with a return loss of better than 10 dB was achieved from 1.4 GHz to 7.3 GHz (1:5.2).

A novel microstrip ring hybrid incorporating a PBG cell

Abstract: An experimental investigation of a novel compact microstrip 180/spl deg/ ring hybrid incorporating a one-dimensional (1-D) slow-wave structure, in the form of perforations on the ring itself, is presented. The size of the hybrid is reduced by 23% due to the slow-wave effect, and this size reduction technique has potential applications in MICs and MMICs. The measured insertion loss is comparable to that of a conventional microstrip hybrid.

Wide-bandwidth millimeter-wave bond-wire interconnects

Abstract: A new type of interconnect has been developed that significantly extends the bandwidth of fixed-length bond-wire interconnects between microwave circuits. This interconnect maximizes bond-wire length, as well as landing pad size while simultaneously extending the cutoff frequency of the interconnect. The bond-wire interconnect is treated as a five-stage low-pass filter where basic filter theory is used to develop an interconnect prototype. Microstrip interconnects are designed using electromagnetic simulators, which match a specific low-pass filter response on a 5-mil thick (127 /spl mu/m) glass substrates. The measurements indicate a return loss greater than 12 dB and an insertion loss from 0.0 to 0.3 dB from DC to 80 GHz using two 17-mil-long (432 /spl mu/m) 1-mil-diameter (25 /spl mu/m) ball bonds with a tolerance of /spl plusmn/2 mil (50 /spl mu/m). For comparison, an uncompensated interconnect with two 17-mil-long (432 /spl mu/m) bond wires has 1-dB insertion loss and 10-dB return loss at 40 GHz and continues to degrade at higher frequencies.

A film bulk acoustic resonator (FBAR) duplexer for USPCS handset applications

Abstract: We will describe the design and measured performance of a duplexer based on film bulk acoustic resonators (FBARs) for the 1900 MHz PCS cellular phone market. Typical specifications for the duplexer require the Tx filter to attenuate frequencies in the Rx band by >40 dB while maintaining a worst-case insertion loss of 3.5 dB over the Tx band. VSWR must be better than 2.2 in the pass-band (8.5 dB return loss). The Rx filter must attenuate the Tx frequencies by >50 dB while maintaining a worst-case insertion loss of 4.2 dB in the Rx band. Again, VSWR must be better than 2.2.

High-isolation W-band MEMS switches

Abstract: This paper presents the design, fabrication and measurement of single, T-match and π-match W-band high-isolation MEMS shunt switches on silicon substrates. The single and T-match design result in -20 dB isolation over the 80-110 GHz range with an insertion loss of 0.25 ± 0.1 dB. The π-match design results in a reflection coefficient lower than -20 dB up to 100 GHz, and an isolation of -30 to -40 dB from 75 to 110 GHz (limited by leakage through the substrate). The associated insertion loss is 0.4 ± 0.1 dB at 90 GHz. To our knowledge, this is the first demonstration of high-performance MEMS switches at W-band frequencies.

Optimal cut for leaky SAW on LiTaO/sub 3/ for high performance resonators and filters

Abstract: The paper describes how the characteristics of leaky surface acoustic wave (LSAW) propagation depend on the thickness of Al grating electrodes on rotated Y-X LiTaO/sub 3/. It is shown that the propagation loss arising from leaky nature changes parabolically with both the grating electrode thickness and rotation angle and becomes zero when electrode thickness and rotation angle are properly determined. This means that even when thick grating electrodes are needed in device design, zero propagation loss is always realized by properly determining the rotation angle. When the grating electrode thickness is 0.07 to 0.1 in wavelength for example, LSAWs on 40-42/spl deg/Y-X LiTaO/sub 3/ give zero propagation loss without deteriorating other characteristics. Ladder-type filters for the 800-MHz range were fabricated, which essentially need thick Al grating electrodes of about 0.1 wavelength thickness. As predicted by theoretical calculation, experimental results showed that if the rotation angle is increased to circa 42/spl deg/ from a conventional value of 38/spl deg/, the insertion loss and shape factor are markedly improved compared with devices based on 36/spl deg/Y-X LiTaO/sub 3/. This is essentially a result of the minimized propagation loss.

High-isolation W-band MEMS switches

Abstract: This paper presents the design, fabrication and measurement of single, T-match and /spl pi/-match W-band high-isolation MEMS shunt switches on silicon substrates. The single and T-match design result in -20 dB isolation over the 80-110 GHz range with an insertion loss of 0.25/spl plusmn/0.1 dB. The /spl pi/-match design results in a reflection coefficient lower than -20 dB up to 100 GHz, and an isolation of -30 to -40 dB from 75 to 110 GHz (limited by leakage through the substrate). The associated insertion loss Is 0.4/spl plusmn/0.1 dB at 90 GHz. To our knowledge, this is the first demonstration of high-performance MEMS switches at W-band frequencies.

A wideband coplanar stripline to microstrip transition

Abstract: A wideband coplanar stripline (CPS)-to-microstrip line was developed. The transition has a simple structure for the ease of fabrication with low cost. The measured performance of two back-to-back transitions exhibits an insertion loss of less than 3 dB and a return loss of better than 10 dB over a bandwidth from 1.3 GHz to 13.3 GHz (1: 10.2). For narrower bandwidth, an insertion loss of less than 1 dB with a return loss of better than 10 dB was achieved from 1.4 GHz to 7.3 GHz (1: 5.2).

Design of an LTCC switch diplexer front-end module for GSM/DCS/PCS applications

Abstract: This paper presents the results of an antenna switch/filter module integrating GSM/DCS/PCS diplexer functions and Rx/Tx antenna switching on a low temperature co-fired ceramic (LTCC) substrate. Although the RF front-end module (FEM) was configured for dual-band (GSM/DCS) applications, the high pass filter function was designed to operate in the PCS band as well. Harmonic filtering was included in the diplexer design, which reduced the filtering requirements for the power amplifier. The 50-ohm in/out FEM utilized GaAs PHEMT switches and associated bias passives surface mounted on the LTCC substrate. S-parameter characterization of the FEM demonstrated excellent insertion and return loss characteristics. For GSM, the return and insertion losses measured at 912 MHz were better than 28 dB and less than 1.7 dB, respectively. Similarly, for DCS applications, the return and insertion losses at 1.77 GHz were better than 19 dB and less than 1.5 dB, respectively. In both cases, the design approach yielded excellent agreement between measured and simulated results.

2 and 4-bit DC-18 GHz microstrip MEMS distributed phase shifters

Abstract: Two and four-bit wideband distributed microstrip phase shifters have been developed on a 21 mil (533 /spl mu/m) silicon substrate for DC-18 GHz operation. Presented here is the first demonstration of microstrip distributed MEMS transmission line (DMTL) designs, periodically loaded by MEMS varactors in series with a fixed value microstrip radial stub. The two-bit design results in a reflection coefficient less than -10 dB,an average insertion loss of -2.8 dB, and a maximum phase shift of 262/spl deg/ at 16 GHz. The four-bit design results in a reflection coefficient less than -9 dB, an average insertion loss of -3.0 dB, and a maximum phase shift of 333/spl deg/ at 16 GHz.

A broadly tunable wavelength-selectable WDM source using a fiber Sagnac loop filter

Abstract: In this letter, we describe a new discretely wavelength-selectable 1.5-/spl mu/m source based on the use of a fiber Sagnac loop filter leading to the possibility of an efficient all-fiber source. The filter has an /spl sim/1.6-dB insertion loss, 14-dB peak-to-valley transmission ratios, and can be tuned to a very precise match with the International Telecommunications Union-wavelength-division-multiplexing grid. We demonstrate 25-channel outputs with precise 50-GHz channel spacings and very large (65 dB) output signal to background noise ratios.