Size Reduction of a MMIC Direct Up-Converter at 44 GHz in Multilayer CPW Technology Using Thin-Film Microstrip Stubs Loading

This paper proposes a novel compact multilayer 44.5-GHz coplanar waveguide (CPW) single-sideband (SSB) subharmonically pumped (SHP) mixer for direct up-conversion GaAs monolithic microwave integrated circuit. It uses previously developed thin-film microstrip (TFMS) and CPW structures for capacitive and inductive loading techniques to drastically reduce its size. The SSB SHP mixer uses 50-MHz in-phase and quadrature signals to directly modulate the second harmonic of a 22.25-GHz carrier to produce the required 44.55-GHz RF output. Two pairs of antiparallel diodes reduce feedthrough of the fundamental 22.25-GHz signal to the RF output while novel CPW/TFMS-based structures provide matching. This 1.2$,times,$1.5$hbox mm^2$chip uses a lumped Wilkinson divider as a local-oscillator divider and a previously developed reduced size 90$^circ$coupler. The SSB SHP mixer acts as an up-converter with a measured conversion gain of$-hbox 10pm hbox 1 ~hbox dB$and the lower sideband suppression is greater than 23 dB across the RF bandwidth of 43.5–45.5 GHz. Additionally, it is shown that the RF port return loss is better than 20 dB, and 2$,times f _ LO$was suppressed by 21 dB over the same band. The circuit also does not require any dc bias. Compared to the conventional SSB SHP mixer, a 70% reduction in circuit area was achieved with better performances.     

W-band CPW RF MEMS circuits on quartz substrates

This paper presents W-band coplanar waveguide RF microelectromechanical system (MEMS) capacitive shunt switches with very low insertion loss (-0.2 to -0.5 dB) and high-isolation (/spl les/ -30 dB) over the entire W-band frequency range. It is shown that full-wave electromagnetic modeling using Sonnet can predict the performance of RF MEMS switches up to 120 GHz. Also presented are W-band 0/spl deg//90/spl deg/ and 0/spl deg//180/spl deg/ switched-line phase shifters with very good insertion loss (1.75 dB/bit at 90 GHz) and a wide bandwidth of operation (75-100 GHz). These circuits are the first demonstration of RF MEMS digital-type phase shifters at W-band frequencies and they outperform their solid-state counterparts by a large margin.     

Compact MMIC CPW and asymmetric CPS branch-line couplers and Wilkinson dividers using shunt and series stub loading

Circuit size may be reduced by up to 60% by embedding series and shunt uniplanar stubs inside the main uniplanar line since this reuses physical space in the longitudinal direction. This size-efficient stub loading of the main uniplanar line results in robust options for designing compact K-band 90/spl deg/ hybrid couplers and Wilkinson dividers. The approach is confirmed by experimental results that agree well with theory up to at least 30 GHz using both coplanar waveguide (CPW) and asymmetric coplanar stripline (ACPS). Furthermore, these couplers and dividers do not use lumped inductors or capacitors and, consequently, have excellent design accuracy even at millimeter-wave frequencies. Additionally, it is shown that it is possible to design an ACPS 90/spl deg/ branch-line coupler without the conventional CPW quarter wavelength transformers used to match the input and output port characteristic impedances.     

Compact triple-band slotted monopole antenna with asymmetrical CPW grounds

By embedding slots into a rectangular patch a triple-band slotted monopole antenna fed by a coplanar waveguide (CPW) with two asymmetrical ground planes can be obtained. The designed antenna, which, including the ground plane, is only 9/spl times/20 mm/sup 2/, can excite resonant modes at 2.43, 5.23 and 7.14 GHz bands with measured impedance bandwidths of 14.4, 8.2 and 16.7%, and average antenna gains of /spl ges/2.4, 4.7 and 6.7 dBi, respectively. The antenna is very compact and suitable for 2.4/5.2 GHz WLAN operations.     

Extrinsic frequency response of a wide-bandwidth metalsemiconductor metal diode

The active area of an interdigitated GaAs MSM diode with 1-μm finger width and spacing is extended with two novel structures, one an integrated tapered coplanar waveguide and another coplanar stripline transmission line. The diodes were illuminated by 5-ps laser pulses of 30-μm in diameter, and the external overall frequency response of the complete system, found by taking the Fourier transform of the detected temporal signal was 2.4 GHz for the coplanar waveguide and 1.4 GHz for the stripline geometry     

V-band CPW 3-dB Tandem coupler using air-bridge structure

We present a uniplanar coplanar waveguide 3-dB tandem coupler operating at V-band frequencies. The uniplanar structure is monolithically fabricated by using two-section parallel-coupled lines and air-bridge crossovers replacing the conventional multilayer or the bonded structures. Due to an optimized tandem structure and nonbonded crossovers minimizing the parasitic components, a maximum coupling of 2.5dB is measured at 62GHz with a 2-dB bandwidth of 83%, while a high directivity factor of 33dB is simultaneously obtained at 58-62GHz. Over the entire design frequency range of 30-90GHz, we achieve good phase unbalance of 90/spl plusmn/6.0/spl deg/, return loss, and isolation lower than -23 and -16dB, respectively.     

High linearity 5.2-GHz power amplifier MMIC using CPW structure technology with a linearizer circuit

A built-in linearizer was applied to improve the linearity in a 5.2-GHz power amplifier microwave monolithic integrated circuit (MMIC), which was undertaken with 0.15-μm AlGaAs/InGaAs D-mode PHEMT technology.The power amplifier (PA) was studied taking into account the linearizer circuit and the coplanar waveguide (CPW) structures. Based on these technologies, the power amplifier, which has a chip size of 1.44 × 1.10 mm~2, obtained an output power of 13.3 dBm and a power gain of 14 dB in the saturation region. An input third-order intercept point (IIP_3) of-3 dBm, an output third-order intercept point (OIP_3) of 21.1 dBm and a power added efficiency (PAE) of 22% were attained, respectively. Finally, the overall power characterization exhibited high gain and high linearity, which illustrates that the power amplifier has a compact circuit size and exhibits favorable RF characteristics. This power circuit demonstrated high RF characterization and could be used for microwave power circuit applications at 5.2 GHz.     

Fully Integrated Broadband CPW Left-Handed Metamaterials Based on GaAs Technology for RF/MMIC Applications

A fully integrated broadband coplanar waveguide left-handed metamaterial medium using GaAs technology for radio frequency/monolithic microwave integrated circuit (RF/MMIC) applications is reported and validated by the full wave simulation and measured results. The unit cell of the fabricated structures has a size of 0.09 mm². The left handedness of the integrated left-handed structure extends from 2.3 to 17.5 GHz. The compactness and broad left-handed operating bandwidth make the presented left-handed metamaterial be well incorporated with RF/MMIC applications.     

K-band monolithic InGaP-InGaAs DCFET amplifier using BCB coplanar waveguide technology

A K-band (20 GHz) monolithic amplifier was developed and fabricated by adopting a low-/spl kappa/ benzocyclobutene (BCB) coplanar waveguide (CPW) line and InGaP-InGaAs doped-channel HFETs (DCFETs). This monolithic microwave integrated circuit (MMIC) utilizes a high impedance BCB CPW microstrip line (Z/sub 0/=70 /spl Omega/) for the biasing circuits, and a Z/sub 0/=50 /spl Omega/ line for the RF signal transmission. The low dielectric constant characteristic of the BCB interlayer is beneficial for a common-ground bridge process, which reduces the parasitics. The calculated loss tan/spl delta/ is 0.036 for the BCB at 20 GHz. The one-stage MMIC amplifier achieves an S/sub 21/ of 5 dB at 20 GHz, which is the first demonstration of the K-band InGaP-InGaAs DCFET monolithic circuit.     

A 24-GHz, +14.5-dBm fully integrated power amplifier in 0.18-/spl mu/m CMOS

A 24-GHz +14.5-dBm fully integrated power amplifier with on-chip 50-/spl Omega/ input and output matching is demonstrated in 0.18-/spl mu/m CMOS. The use of substrate-shielded coplanar waveguide structures for matching networks results in low passive loss and small die size. Simple circuit techniques based on stability criteria derived result in an unconditionally stable amplifier. The power amplifier achieves a power gain of 7 dB and a maximum single-ended output power of +14.5-dBm with a 3-dB bandwidth of 3.1 GHz, while drawing 100 mA from a 2.8-V supply. The chip area is 1.26 mm/sup 2/.     

A 60-GHz uniplanar MMIC 4/spl times/ subharmonic mixer

A uniplanar GaAs monolithic microwave integrated circuit /spl times/4 subharmonic mixer (SHM) has been fabricated for 60-GHz-band applications using an antiparallel diode pair in finite ground coplanar (FGC) waveguide technology. This mixer is designed to operate at an RF of 58.5-60.5 GHz, an IF of 1.5-2.5 GHz, and an LO frequency of 14-14.5 GHz. FGC transmission-line structures used in the mixer implementation were fully characterized using full-wave electromagnetic simulations and on-wafer measurements. Of several mixer configurations tested, the best results show a maximum conversion loss of 13.2 dB over the specified frequency range with a minimum local-oscillator power of 3 dBm. The minimum upper sideband conversion loss is 11.3 dB at an RF of 58.5 GHz and an IF of 2.5 GHz. This represents excellent performance for a 4/spl times/ SHM operating at 60 GHz.     

32 GHz MMIC distributed amplifier based on n-channel SiGe MODFETs

For the first time the fabrication of a distributed amplifier based on n-type Si/SiGe-MODFETs is presented. The realised amplifier consists of six identical stages and has a gain of 5.5 dB. The bandwidth of this amplifier is 32 GHz. The gain ripple up to this frequency is /spl plusmn/0.8 dB. The return losses at the input and output are better than 10 dB. Using a coplanar waveguide layout for the amplifier no via-holes and backside processing is needed. The MMIC has a size of 0.9/spl times/3.2 mm/sup 2/.     

A Ka-band MMIC oscillator utilizing a labyrinthine PBG resonator

A Ka-band monolithic microwave integrated circuit (MMIC) oscillator was implemented by using a coplanar waveguide photonic bandgap (PBG) resonator and a 0.1-/spl mu/m GaAs pseudomorphic high electron mobility transistor. A coplanar labyrinthine one-dimensional PBG resonator was used for reduction in MMIC size. The fabricated MMIC oscillator had an output power of 6.5dBm at 30.3GHz and a free-running phase noise of -80dBc/Hz at 100-kHz offset.     

Size-reduction techniques for CPW and ACPS structures

In coplanar-waveguide technology, there is a possibility of locating shunt and series matching stubs inside the center conductor of the transmission line. This principle can be used to reduce of the dimensions of microwave components such as monolithic microwave integrated circuits. This paper discusses the concept and presents the design of a reduced-size Wilkinson divider based on the realization of short-circuit series stubs in the signal conductor of an asymmetric coplanar stripline     

A V-band quasi-optical GaAs HEMT monolithic integrated antenna and receiver front end

A single-chip monolithic integrated V-band folded-slot antenna with two Schottky-barrier diodes and a local oscillator source is developed as a quasi-optical receiver for the first time. The monolithic microwave integrated circuit consists of a voltage-controlled oscillator (VCO), a coplanar waveguide (CPW)-to-slotline transition, a low-pass filter, a folded-slot antenna, and a 180/spl deg/ single balanced mixer. The chip is fabricated based on the 0.15-/spl mu/m GaAs high electron-mobility transistor technology and the overall chip size is 3/spl times/1.5 mm/sup 2/. A finite-difference time-domain method solver is also developed for analyzing the embedded impedance characteristics of the folded-slot antenna to design the mixer. The chip is placed on an extended hemispherical silicon substrate lens to be a quasi-optical receiver. The performance of the receiver is verified by experimental measurements. The VCO has achieved a tuning range from 61.9 to 62.5 GHz and approximately 9.3-dBm output power. The CPW-to-slotline transition has bandwidth from 50 to 70 GHz. The mixer results in 15-dB single-sideband conversion loss and the receiving patterns of the IF power are also measured.     

低阻硅衬底上形成的低损耗共平面波导传输线

在厚膜多孔硅 (PS) /氧化多孔硅 (OPS)衬底上 ,结合聚酰亚胺涂层改善表面 ,研制低损耗、高性能射频 (RF) /微波 (MW)共平面波导CPW(CoplanarWaveguide) .通过在N和P型硅上形成不同厚度PS膜 ,并对其上的CPW进行分析比较 ,厚膜PS与石英的共面波导插入损耗非常接近 ,远小于在 2 0 0 0Ω·cm高阻硅上形成的多晶硅 -氧化硅组合衬底 :在 0 33GHz范围 ,插入损耗小于 5dB/ 1.2cm ;33 4 0GHz范围 ,小于 7.5dB/ 1.2cm .     

Short wavelength coplanar waveguide employing PAGS on silicon substrate for application to miniaturised passive components on RFIC

A short wavelength coplanar waveguide employing a periodically arrayed grounded-strip structure on a silicon substrate was developed for application to miniaturised passive components on a silicon substrate. Using the coplanar waveguide, a highly miniaturised impedance transformer was realised on a silicon substrate. The impedance transformer exhibited good RF performances from 1 to 40 GHz, and its size was 0.01 mm², which is 6.99% of a conventional one.     

Novel design for small-size coplanar waveguide frequency tripler

This letter presents a novel design for a small-size coplanar waveguide frequency tripler. In this study, a new BPF has been replaced the conventional stub lines in the output termination of the multiplier. Not only enhance the performance of the tripler, but also reduce the whole circuit size. to 2.125/spl times/2.275 cm/sup 2/ in the frequency 0.8/2.4 GHz, The spurious suppressions are 37.48, 33.38, and 32.08 dBc for the 1st, 2nd, and 4th harmonics, respectively. It reveals the best output power of -1.92 dBm for a 0 dBm input signal and maximum conversion gain of -1.92 dB. It is very useful for applications in the wireless communication and radar systems.     

Miniaturised two-stage balanced Ku-band CPW MMIC amplifier using impedance transforming couplers

A two-stage balanced Ku-band coplanar waveguide amplifier design is presented which has been miniaturised by using impedance transforming couplers which considerably reduce the required matching networks to the MESFETs. The amplifier, measuring only 2*1.7 mm/sup 2/, exhibits a gain of 13.7 dB with less than +or-0.2 dB of ripple over the range 14-16 GHz.<>     

X-band brick wall antenna fed by CPW

A brick wall antenna fed by a coplanar waveguide is introduced. This antenna can be considered as an eleven element array of reduced size. Analysis is carried out both theoretically and experimentally. The proposed antenna is designed to work in the X-band ~9.5 GHz. The return loss, radiation pattern, and antenna gain of the proposed antenna are presented and briefly discussed. The antenna has several advantages, such as ease of fabrication, good control of input impedance, small cross polarisation level, and high directivity