Broadband Self-Compensating Phase Shifter Combining Delay Line and Equal-Length Unequal-Width Phaser

In this paper, a broadband self-compensating phase shifter is presented and developed on the basis of substrate integrated waveguide (SIW) technology. Since the SIW is a dispersive guided-wave structure, the effective bandwidth of SIW phase shifter is usually narrow. Phase shifts generated by two different structures, namely delay line and equal-length unequal-width phase shifter, are discovered in this work to present interesting opposite tendencies versus frequency. Therefore, an appropriate combination of them will make the phase shift almost constant over a very wide band. Design equations and process are given following a mathematical analysis. To demonstrate the interesting and useful features of the proposed technique, a 90 $^{circ}$ and a 45 $^{circ}$ self-compensating phase shifters are designed as showcases with standard printed circuit board process. For the 90$^{circ}$ version, the measured amplitude and phase imbalance between the two paths are within 0.2 dB and 2.5$^{circ}$ , respectively, within the frequency band from 25.11 to 39.75 GHz, or around 49% bandwidth. The return loss is found to be better than 12 dB within the frequency band of interest. The 45 $^{circ}$ one has the similar excellent performance. The measurements demonstrate that this type of SIW phase shifter is superior to all of its counterparts.      

180$^{circ}$ and 90$^{circ}$ Phase Shifting Networks With an Octave Bandwidth and Small Phase Errors

A new phase shifting network for both 180 $^{circ}$ and 90 $^{circ}$ phase shift with small phase errors over an octave bandwidth is presented. The theoretical bandwidth is 67% for the 180$^{circ}$ phase bit and 86% for the 90$^{circ}$ phase bit when phase errors are $pm 2^{circ}$. The proposed topology consists of a bandpass filter (BPF) branch, consisting of a LC resonator and two shunt quarter-wavelength transmission lines (TLs), and a reference TL. A theoretical analysis is provided and scalable parameters are listed for both phase bits. To test the theory, phase shifting networks from 1 GHz to 3 GHz were designed. The measured phase errors of the 180$^{circ}$ and the 90$^{circ}$ phase bit are $pm 3.5^{circ}$ and $pm 2.5^{circ}$ over a bandwidth of 73% and 102% while the return losses are better than 18 dB and 12 dB, respectively.      

$S$ - and $C$ -Band Ultra-Compact Phase Shifters Based on All-Pass Networks

Ultra-compact phase shifters are presented. The proposed phase-shifting circuits utilize the lumped element all-pass networks. The transition frequency of the all-pass network, which determines the size of the circuit, is set to be much higher than the operating frequency. This results in a significantly small chip size of the phase shifter. To verify this methodology, 5-bit phase shifters have been fabricated in the $S$ - and $C$ -band. The $S$ -band phase shifter, with a chip size of 1.87 mm $,times,$0.87 mm (1.63 mm $^{2}$), has achieved an insertion loss of ${hbox{6.1 dB}} pm {hbox{0.6 dB}}$ and rms phase-shift error of less than 2.8$^{circ}$ in 10% bandwidth. The $C$ -band phase shifter, with a chip size of 1.72 mm $,times,$0.81 mm (1.37 mm $^{2}$), has demonstrated an insertion loss of 5.7 dB $pm$ 0.8 dB and rms phase-shift error of less than 2.3 $^{circ}$ in 10% bandwidth.      

Design of a Beam Switching/Steering Butler Matrix for Phased Array System

A compact broadband 8-way Butler matrix integrated with tunable phase shifters is proposed to provide full beam switching/steering capability. The newly designed multilayer stripline Butler matrix exhibits an average insertion loss of 1.1 dB with amplitude variation less than $pm$2.2 dB and an average phase imbalance of less than 20.7$^{circ}$ from 1.6 GHz to 2.8 GHz. The circuit size is only $160times 100 {rm mm}^{2}$, which corresponds to an 85% size reduction compared with a comparable conventional microstrip 8-way Butler matrix. The stripline tunable phase shifter is designed based on the asymmetric reflection-type configuration, where a Chebyshev matching network is utilized to convert the port impedance from 50 $Omega$ to 25 $Omega$ so that a phase tuning range in excess of 120$^{circ}$ can be obtained from 1.6 GHz to 2.8 GHz. To demonstrate the beam switching/steering functionality, the proposed tunable Butler matrix is applied to a 1 $times$ 8 antenna array system. The measured radiation patterns show that the beam can be fully steered within a spatial range of 108 $^{circ}$.      

A 10:1 Unequal Wilkinson Power Divider Using Coupled Lines With Two Shorts

A novel unequal Wilkinson power divider is presented. A coupled-line section with two shorts is proposed to realize the high characteristic impedance line, which cannot be implemented by conventional microstrip fabrication technique due to fabrication limitation. The proposed coupled-line structure is compatible with single layer integration and can be easily designed based on an even-odd mode analysis. As a design example, a 10:1 Wilkinson power divider at 2 GHz is fabricated and measured. The measured $-10~{rm dB}$ bandwidth of $S_{11}$ is about 16%, and the isolation $S_{32}$ is better than $-20~{rm dB}$ . The measured amplitude balance between output port 2 and port 3 is between $-10.20~{rm dB}$ and $-9.52~{rm dB}$, and the corresponding phase difference is between 0$^{circ}$ and 4.6$^{circ}$.      

A 36–80 GHz High Gain Millimeter-Wave Double-Balanced Active Frequency Doubler in SiGe BiCMOS

This letter presents a high conversion gain double-balanced active frequency doubler operating from 36 to 80 GHz. The circuit was fabricated in a 200 GHz ${rm f}_{rm T}$ and ${rm f}_{max}$ 0.18 $mu$m SiGe BiCMOS process. The frequency doubler achieves a peak conversion gain of 10.2 dB at 66 GHz. The maximum output power is 1.7 dBm at 66 GHz and ${-}3.9$ dBm at 80 GHz. The maximum fundamental suppression of 36 dB is observed at 60 GHz and is better than 20 dB from 36 to 80 GHz. The frequency doubler draws 41.6 mA from a nominal 3.3 V supply. The chip area of the active frequency doubler is 640 $mu$m $,times,$424 $mu$m (0.272 mm $^{2}$) including the pads. To the best of authors' knowledge, this active frequency doubler has demonstrated the highest operating frequency with highest conversion gain and output power among all other silicon-based active frequency doublers reported to date.      

Quasi Microstrip Leaky-Wave Antenna With a Two-Dimensional Beam-Scanning Capability

A quasi microstrip leaky-wave antenna (QMLWA) with a two-dimensional (2-D) beam-scanning capability is presented in this paper. QMLWA consists of two half-width microstrip leaky-wave antennas with a phase-shifter. This new type of microstrip leaky-wave antenna has the advantages of reducing size, 2-D beam-scanning and suppressing back lobes. The main lobe scanning in H-plane ($y-z$ plane) is achieved through varying the operating frequency. When the operating frequency increases from 4.4–6 GHz, the main lobe scans from 84 $^{circ}$ to 26 $^{circ}$ in H-plane continuously. The main lobe steers in quasi-E-plane with varying the phase difference between two half-width microstrip leaky-wave antennas. The lobe scans from 78$^{circ}$ to 103$^{circ}$ in quasi-E-plane at 5.4 GHz. The experimental results show this short QMLWA (about 2 wavelengths) leaks power effectively. The back lobe in H-plane of QMLWA is suppressed 13 dB as compared with the conventional whole width MLWA at 5.4 GHz as example. The H-plane radiation characteristics of QMLWA are mainly determined by the width $s$ of half-width MLWA and the distance $D$ between two half-width MLWA together. This size-reduced QMLWA is useful in the automotive radar system and air traffic control.      

10-GHz and 20-GHz Channel Spacing High-Resolution AWGs on InP

This letter reports on 10-GHz and 20-GHz channel-spacing arrayed waveguide gratings (AWGs) based on InP technology. The dimensions of the AWGs are 6.8$,times,$8.2 mm$^{2}$ and 5.0$,times,$6.0 mm$^{2}$, respectively, and the devices show crosstalk levels of $-$12 dB for the 10-GHz and $-$17 dB for the 20-GHz AWG without any compensation for the phase errors in the arrayed waveguides. The root-mean-square phase errors for the center arrayed waveguides were characterized by using an optical vector network analyzer, and are 18 $^{circ}$ for the 10-GHz AWG and 28$^{circ}$ for the 10-GHz AWG.      

Temperature-Insensitive Dual-Comb Filter Based on Multimode Interference Ti : LiNbO $_{3}$ Waveguide

A temperature-insensitive dual-comb filter has been demonstrated for the first time by multimode interference based on a Ti : LiNbO$_{3}$ channel waveguide. The phase difference between comb filters was about 180 $^{circ}$. We only observed less than ${pm}$0.125-nm variation of the center wavelength of the filter during temperature change from 20 $^{circ}$C to 50 $^{circ}$C. The measured extinction ratio and channel spacing of the comb filter were about ${-}$25 dB and 3.2 THz, respectively.      

A 30–100 GHz Wideband Sub-Harmonic Active Mixer in 90 nm CMOS Technology

This letter presents a 30–100 GHz wideband and compact fully integrated sub-harmonic Gilbert-cell mixer using 90 nm standard CMOS technology. The sub-harmonic pumped scheme with advantages of high port isolation and low local oscillation frequency operation is selected in millimeter-wave mixer design. A distributed transconductance stage and a high impedance compensation line are introduced to achieve the flatness of conversion gain over broad bandwidth. The CMOS sub-harmonic Gilbert-cell mixer exhibits ${-}{hbox{1.5}} pm {hbox{1.5}}$ dB measured conversion gain from 30 to 100 GHz with a compact chip size of 0.35 mm$^{2}$. The OP$_{1 {rm dB}}$ of the mixer is ${-}$ 10.4 dBm and ${-}$9.6 dBm at 77 and 94 GHz, respectively. To the best of our knowledge, the monolithic microwave integrated circuit is the first CMOS Gilbert-cell mixer operating up to 100 GHz.      

Novel Composite Phase-Shifting Transmission-Line and Its Application in the Design of Antenna Array

A novel composite phase-shifting transmission line (TL) with designable characteristics is presented, which can be used to achieve arbitrary phase of the transmission coefficient at any required frequency with a certain length of the TL. An empirical formula is given of the relationship between the phase and physical length of the composite TL at a required frequency. A sample of 0$^{circ}$ phase-shifting TL is designed in details, and is verified by the full-wave simulation. At the required frequency of 5 GHz, the amplitude of ${rm S}_{21}$ is equal to $-0.23~{rm dB}$ with a phase of $-0.467^{circ}$. The electric length is only $0.212lambda_{0}$ , which has been decreased by 68.5% compared to the conventional microstrip line. Using the proposed composite TL, an antenna array is designed with two radiation patches excited by the novel series feed-line. The detailed procedure of such design is presented. The lowest reflection coefficient is exactly achieved at the required frequency of 5 GHz. The maximum radiation is obtained at $theta_{0}=0^{circ}$ , which indicates that the 0$^{circ}$ phase-shifting TL works very well. The sample is also fabricated and good agreements between simulation and measurement results are obtained.      

A 0.13 $mu$ m CMOS Quad-Band GSM/GPRS/EDGE RF Transceiver Using a Low-Noise Fractional-N Frequency Synthesizer and Direct-Conversion Architecture

This paper presents a single-chip CMOS quad-band (850/900/1800/1900 MHz) RF transceiver for GSM/GPRS/EDGE applications which adopts a direct-conversion receiver, a direct-conversion transmitter and a fractional-N frequency synthesizer with a built-in DCXO. In the GSM mode, the transmitter delivers 4 dBm of output power with 1$^{circ}$ RMS phase error and the measured phase noise is ${-}$164.5 dBc/Hz at 20 MHz offset from a 914.8$~$MHz carrier. In the EDGE mode, the TX RMS EVM is 2.4% with a 0.5 $~$dB gain step for the overall 36 dB dynamic range. The RX NF and IIP3 are 2.7 dB/ ${-}$12 dBm for the low bands (850/900 MHz) and 3 dB/${-}$ 11 dBm for the high bands (1800/1900 MHz). This transceiver is implemented in 0.13 $mu$m CMOS technology and occupies 10.5 mm$^{2}$ . The device consumes 118 mA and 84 mA in TX and RX modes from 2.8 V, respectively and is housed in a 5$,times,$ 5 mm$^{2}$ 40-pin QFN package.      

A $Q$ -Band Four-Element Phased-Array Front-End Receiver With Integrated Wilkinson Power Combiners in 0.18-$mu{{hbox{m}}}$ SiGe BiCMOS Technology

A four-element phased-array front-end receiver based on 4-bit RF phase shifters is demonstrated in a standard 0.18- $mu{{hbox{m}}}$ SiGe BiCMOS technology for $Q$-band (30–50 GHz) satellite communications and radar applications. The phased-array receiver uses a corporate-feed approach with on-chip Wilkinson power combiners, and shows a power gain of 10.4 dB with an ${rm IIP}_{3}$ of $-$13.8 dBm per element at 38.5 GHz and a 3-dB gain bandwidth of 32.8–44 GHz. The rms gain and phase errors are $leq$1.2 dB and $leq {hbox{8.7}}^{circ}$ for all 4-bit phase states at 30–50 GHz. The beamformer also results in $leq$ 0.4 dB of rms gain mismatch and $leq {hbox{2}}^{circ}$ of rms phase mismatch between the four channels. The channel-to-channel isolation is better than $-$35 dB at 30–50 GHz. The chip consumes 118 mA from a 5-V supply voltage and overall chip size is ${hbox{1.4}}times {hbox{1.7}} {{hbox{mm}}}^{2}$ including all pads and CMOS control electronics.      

A 16–44 GHz Compact Doubly Balanced Monolithic Ring Mixer

A novel and compact 16–44 GHz ultra-broadband doubly balanced monolithic ring mixer for Ku- to Ka-band applications implemented with a 0.15-$mu$m pHEMT process is presented. The proposed mixer is composed of a C-band miniature spiral balun and a 180$^{circ}$ hybrid formed with an interdigital coupler, a low-pass $pi$-network, and a high-pass T-network. The 180$^{circ}$ hybrid eliminates the use of a cross-over structure for application in the balanced mixer, as well as provides an output port for the RF extraction of up-converter application. This proposed configuration leads to a die size of less than 0.8$,times,$ 0.8 mm$^{2}$ . From the measured results, the mixer exhibits an 11–14 dB conversion loss, a 27–50 dB high LO-to-IF isolation over 16–44 GHz RF/LO bandwidth, and a 1-dB compression power of 14 dBm for both down- and up-converter applications.      

W-Band Active Down-Conversion Mixer in Bulk CMOS

A W-band (76–77 GHz) active down-conversion mixer has been demonstrated using low leakage (higher ${rm V}_{{rm T}}$) NMOS transistors of a 65-nm digital CMOS process with 6 metal levels. It achieves conversion gain of ${-}8$ dB at 76 GHz with a local oscillation power of 4 dBm (${sim-}2$ dBm after de-embedding the on-chip balun loss), and 3 dB bandwidth of 3 GHz. The SSB noise figures are 17.8–20 dB (11.3–13.5 dB after de-embedding on-chip input balun loss) between 76 and 77 GHz. ${rm IP}_{1{rm dB}}$ is ${-}6.5$ dBm and IIP3 is 2.5 dBm (${sim-}13$ and ${sim}-4$ dBm after de-embedding the on-chip balun loss). The mixer consumes 5 mA from a 1.2 V supply.      

Compact $S$ -/$Ka$-Band CMOS Quadrature Hybrids With High Phase Balance Based on Multilayer Transformer Over-Coupling Technique

This paper presents compact CMOS quadrature hybrids by using the transformer over-coupling technique to eliminate significant phase error in the presence of low-$Q$ CMOS components. The technique includes the inductive and capacitive couplings, where the former is realized by employing a tightly inductive-coupled transformer and the latter by an additional capacitor across the transformer winding. Their phase balance effects are investigated and the design methodology is presented. The measurement results show that the designed 24-GHz CMOS quadrature hybrid has excellent phase balance within ${pm}{hbox{0.6}}^{circ}$ and amplitude balance less than ${pm} {hbox{0.3}}$ dB over a 16% fractional bandwidth with extremely compact size of 0.05 mm$^{2}$. For the 2.4-GHz hybrid monolithic microwave integrated circuit, it has measured phase balance of ${pm}{hbox{0.8}}^{circ}$ and amplitude balance of ${pm} {hbox{0.3}}$ dB over a 10% fractional bandwidth with a chip area of 0.1 mm$^{2}$ .      

Operation of a 25-Gb/s Direct Modulation Ridge Waveguide MQW-DFB Laser up to 85 $^{circ}$ C

We demonstrated a 25-Gb/s direct modulation up to 85 $^{circ}$C with a 1.3- $mu$m InGaAlAs ridge-waveguide multiple-quantum-well distributed-feedback laser. The dependence of the relaxation oscillation frequency on current was 3.3 GHz/mA$^{1 / 2}$, and this is the highest value ever reported for 200-$mu$m-long lasers in the 1.3-$mu$m wavelength region. The $alpha$ parameter was around 2.7 at 25 $^{circ}$C, and an error-free operation after a 10-km single-mode fiber transmission was obtained up to 85 $^{circ}$C.      

A 3–10 GHz CMOS UWB Low-Noise Amplifier With ESD Protection Circuits

A low-power fully integrated low-noise amplifier (LNA) with an on-chip electrostatic-static discharge (ESD) protection circuit for ultra-wide band (UWB) applications is presented. With the use of a common-gate scheme with a ${rm g}_{rm m}$ -boosted technique, a simple input matching network, low noise figure (NF), and low power consumption can be achieved. Through the combination of an input matching network, an ESD clamp circuit has been designed for the proposed LNA circuit to enhance system robustness. The measured results show that the fabricated LNA can be operated over the full UWB bandwidth of 3.0 to 10.35 GHz. The input return loss $({rm S}_{11})$ and output return loss $({rm S}_{22})$ are less than ${-}8.3$ dB and ${-}9$ dB, respectively. The measured power gain $({rm S}_{21})$ is $11 pm 1.5$ dB, and the measured minimum NF is 3.3 dB at 4 GHz. The dc power dissipation is 7.2 mW from a 1.2 V supply. The chip area, including testing pads, is 1.05 mm$,times,$ 0.73 mm.      

$hbox{TiN/ZrO}_{2}$/Ti/Al Metal–Insulator–Metal Capacitors With Subnanometer CET Using ALD-Deposited $hbox{ZrO}_{2}$ for DRAM Applications

We provide the first report of the structural and electrical properties of $hbox{TiN/ZrO}_{2}$/Ti/Al metal–insulator–metal capacitor structures, where the $hbox{ZrO}_{2}$ thin film (7–8 nm) is deposited by ALD using the new zirconium precursor ZrD-04, also known as Bis(methylcyclopentadienyl) methoxymethyl. Measured capacitance–voltage ($C$– $V$) and current–voltage ( $I$–$V$) characteristics are reported for premetallization rapid thermal annealing (RTP) in $hbox{N}_{2}$ for 60 s at 400 $^{circ}hbox{C}$, 500 $^{circ}hbox{C}$, or 600 $^{ circ}hbox{C}$. For the RTP at 400 $^{circ}hbox{C}$ , we find very low leakage current densities on the order of nanoamperes per square centimeter at a gate voltage of 1 V and low capacitance equivalent thickness values of $sim$ 0.9 nm at a gate voltage of 0 V. The dielectric constant of $ hbox{ZrO}_{2}$ is 31 $pm$ 2 after RTP treatment at 400 $^{circ}hbox{C}$.      

Heterogeneous High-Performance Quantum-Cascade Laser Sources for Broad-Band Tuning

A heterogeneous high-performance quantum-cascade laser gain chip comprising two bound-to-continuum active region designs emitting at 8.2 and 9.3 $mu$m is presented. Its extrapolated gain spectrum has a full-width at half-maximum (FWHM) of 350 cm$^{ - 1}$. Though a broad gain bandwidth invariably results in a reduced gain cross section, devices with a high-reflection coated back facet still lase continuous-wave (CW) up to a temperature of 50 $^{circ}$C and demonstrates output powers in excess of 100 mW at 30$^{circ}$C. Such high performance was achieved by designing the waveguide in a buried heterostructure fashion and epi-down mounting on a diamond submount, resulting in a thermal resistance of only 4.8 K/W. In pulsed mode, we reached a peak output power of 1 W at room temperature. Finally, in order to prove the usability for broad-band tuning, this chip was antireflection coated on the front facet with a residual reflectivity of $≪ {hbox {2.5}} times {hbox {10}}^{-3}$ and used in our external cavity (EC) setup operated at room temperature. In pulsed mode, we were able to tune the gain chip over 292 cm $^{-1}$, which is 25% of center frequency. In CW, we reached a coarse tuning range of 201 cm$^{-1}$ (18%) and an output power in excess of 135 mW at the gain maximum at 15$^{circ}$C. This gain chip enabled CW room temperature EC tuning with output powers in excess of 20 mW over 172 cm 相似文献