A 10–40 GHz Broadband Subharmonic Monolithic Mixer in 0.18 $mu$ m CMOS Technology

A 10–40 GHz broadband subharmonic monolithic passive mixer using the standard 0.18 $mu$ m CMOS process is demonstrated. The proposed mixer is composed of a two-stage Wilkinson power combiner, a short stub and a low-pass filter. Likewise, the mixer utilizes a pair of anti-parallel gate-drain-connected diodes to achieve subharmonic mixing mechanism. The two-stage Wilkinson power combiner is used to excite a radio frequency (RF) and local oscillation (LO) signals into diodes and to perform broadband operation. The low-pass filter supports an IF frequency range from dc to 2.5 GHz. This proposed configuration leads to a die size of less than 1.1$,times,$ 0.67 mm$^{2}$ . The measured results demonstrate a conversion loss of 15.6–17.6 dB, an LO-to-RF isolation better than 12 dB, a high 2LO-to-RF isolation of 51–59 dB over 10–40 GHz RF bandwidth, and a 1 dB compression power of 8 dBm.      

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.      

一种新型毫米波8路功分器/合成器的设计

设计了一种Q波段8路功分器/合成器。利用波导功分器及微带功分器混合设计,提出了波导-微带4路功分器与3 dB Wilkinson电桥一体化设计思想,设计出一种较高隔离度,结构紧凑的新型8路功率分配器/合成器。通过高频电磁仿真软件(HFSS)仿真设计,在42 GHz~47 GHz频带范围内,8路分配器输出端口反射损耗优于-19 dB;8路输出端口的幅度不平衡度小于0.25 dB,相位不平衡度小于0.5o,插损小于0.25 dB;4个输出口之间的隔离度大于9 dB,是一种较为理想的8路功率分配器/合成器,在实际小体积高合成效率要求的固态功率合成领域,以及具有小体积的多路信道实现中,具有较高的应用价值。     

A Millimeter-Wave (40–45 GHz) 16-Element Phased-Array Transmitter in 0.18-$mu$ m SiGe BiCMOS Technology

This paper demonstrates a 16-element phased-array transmitter in a standard 0.18-mum SiGe BiCMOS technology for Q-band satellite applications. The transmitter array is based on the all-RF architecture with 4-bit RF phase shifters and a corporate-feed network. A 1:2 active divider and two 1:8 passive tee-junction dividers constitute the corporate-feed network, and three-dimensional shielded transmission-lines are used for the passive divider to minimize area. All signals are processed differentially inside the chip except for the input and output interfaces. The phased-array transmitter results in a 12.5 dB of average power gain per channel at 42.5 GHz with a 3-dB gain bandwidth of 39.9-45.6 GHz. The RMS gain variation is < 1.3 dB and the RMS phase variation is < for all 4-bit phase states at 35-50 GHz. The measured input and output return losses are < -10 dB at 36.6-50 GHz, and <-10 dB at 37.6-50 GHz, respectively. The measured peak-to-peak group delay variation is plusmn 20 ps at 40-45 GHz. The output P_-1dB is -5plusmn1.5 dBm and the maximum saturated output power is - 2.5plusmn1.5 dBm per channel at 42.5 GHz. The transmitter shows <1.8 dB of RMS gain mismatch and < 7deg of RMS phase mismatch between the 16 different channels over all phase states. A - 30 dB worst-case port-to-port coupling is measured between adjacent channels at 30-50 GHz, and the measured RMS gain and phase disturbances due to the inter-channel coupling are < 0.15 dB and < 1deg, respectively, at 35-50 GHz. All measurements are obtained without any on-chip calibration. The chip consumes 720 mA from a 5 V supply voltage and the chip size is 2.6times3.2 mm².     

Planar Probe Coaxial-Waveguide Power Combiner/Divider

A novel axially symmetric oversized coaxial waveguide power combiner/divider, which utilizes a planar probe array to transform multiway input to a central oversized coaxial waveguide, is presented in this paper. The use of a coaxial waveguide allows standard transverse electromagnetic design theory to be used, and the characteristics of the coaxial taper transition and the planar probe array are analyzed in detail. A design procedure is also established for the structure. A ten-way planar probe coaxial-waveguide power combiner/divider over the $Ku$-band is designed and measured. The measured results show a reasonable agreement with the simulated results. The measured 15-dB return-loss bandwidth is approximately 4.3 GHz, and a maximum amplitude imbalance of ${pm} {hbox{1}}$ dB and a phase imbalance of $pm {hbox{5}}^{circ}$ are observed in the 11.5–16-GHz band. Furthermore, the isolation between the peripheral ports is also discussed.      

Millimeter-wave-band amplifier and mixer MMICs using a broad-band45° power divider/combiner

This paper demonstrates millimeter-wave-band amplifier and mixer monolithic microwave integrated circuits (MMIC's) using a broad-band 45° power divider/combiner. At first, we propose a broad-band 45° power divider/combiner, which combines a Wilkinson divider/combiner, 45° delay line, and 90° short stub. A coupling loss of 4.0±0.2 dB and a return loss and an isolation of more than 19 dB with 45±1° phase difference was obtained from 17 to 22 GHz for the fabricated K-band MMIC 45° power divider/combiner. Next, a parallel amplifier using the broad-band 45° power divider/combiner, which can be used in a power-combining circuit configuration requiring no isolator, is shown. Comparing the transmitter intermodulation generated in the parallel amplifier using the broad-band 45° power divider/combiner and that generated in the one using the conventional type, the broad-band suppression effect was confirmed. Finally, an application of the broad-band 45° power divider/combiner to a single-sideband (SSB) subharmonically pumped (SHP) mixer requiring no IF switch is shown. In an RF frequency range from 22.89 to 26.39 GHz, the fabricated K-band MMIC mixer achieved (for up-conversion) the good results of more than -13-dB conversion gain and more than 24-dB image-rejection ratio. These contribute significantly to the miniaturization of millimeter-wave communication equipment     

A 40–50-GHz SiGe 1 : 8 Differential Power Divider Using Shielded Broadside-Coupled Striplines

This paper presents a 1 : 8 differential power divider implemented in a commercial SiGe BiCMOS process using fully shielded broadside-coupled striplines integrated vertically in the silicon interconnect stackup. The 1 : 8 power divider is only 1.12 $,times,$1.5 mm$^{2}$ including pads, and shows 0.4-dB rms gain imbalance and $≪ {hbox{3}}^{circ}$ rms phase imbalance from 40 to 50 GHz over all eight channels, a measured power gain of ${hbox{14.9}} pm {hbox{0.6}}$ dB versus a passive divider at 45 GHz, and a 3-dB bandwidth from 37 to 52 GHz. A detailed characterization of the shielded broadside-coupled striplines is presented and agrees well with simulations. These compact lines can be used for a variety of applications in SiGe/CMOS millimeter-wave circuits, including differential signal distribution, miniature power dividers, matching networks, filters, couplers, and baluns.      

18–40-GHz Beam-Shaping/Steering Phased Antenna Array System Using Fermi Antenna

This paper concerns 18-40 GHz 1times 16 beam shaping and 1times 8 beam steering phased antenna arrays (PAAs) realized on a single low-cost printed circuit board substrate. The system consists of a wideband power divider with amplitude taper for sidelobe suppression, wideband microstrip-to-slotline transition, a low-cost true time piezoelectric transducer (PET)-controlled phase shifter, and wideband Fermi antennas with corrugations along the sides. A coplanar stripline is used under a PET-controlled phase shifter, which can generate 50% more phase shift compared to the perturbation on microstrip lines previously published. The systems are fabricated using electro-fine-forming microfabrication technology. Measured return loss is better than 10 dB from 18 to 40 GHz for both the beam-shaping and beam-steering PAAs. The beam-shaping PAA has a 12deg 3-dB beamwidth broadening range. The sidelobe ratios (SLRs) are 27, 23, and 20 dB at 20, 30, and 40 GHz, respectively, without perturbation. The SLRs are 20, 16, and 15 dB at 20, 30, and 40 GHz with maximum perturbation. The beam-steering PAA has a 36deg (-17deg to +19deg ) beam-scanning range measured at 30 GHz.     

Miniature Four-Way and Two-Way 24 GHz Wilkinson Power Dividers in 0.13 μm CMOS

This letter presents 24 GHz four-way and two-way miniature Wilkinson power dividers (PDs) in a standard CMOS technology. The chip area is significantly reduced using a lumped-element design, and the effective areas of four-way and two-way Wilkinson dividers are 0.33 times 0.33 mm² and 0.12 times 0.29 mm², respectively. The four-way Wilkinson divider results in an insertion loss <2.4 dB, an input/output return loss better 15.5 dB, and a port-to-port isolation >24.7 dB from 22 to 26 GHz. The two-way Wilkinson divider results in an insertion loss <1.4 dB, an input/output return loss better 8.9 dB, and a port-to-port isolation >14.8 dB from 22 to 26 GHz. To the author's knowledge, this is the first demonstration of 24 GHz four-way Wilkinson PD in a standard CMOS technology.     

Implementation of a Microstrip Square Planar $N$-Way Metamaterial Power Divider

This paper describes a compact square-shaped 20-way metamaterial power divider implemented in microstrip technology and lumped capacitors and inductors. The divider comprises 12 square tiles exhibiting left-handed behavior and 13 square tiles exhibiting right-handed behavior arranged in a checkerboard tessellation (or mosaic). The divider relies upon the infinite wavelength phenomena in two dimensions and this requires the left-handed tiles have an insertion phase between any two of its sides equal to, but with opposite sign, of that of the right-handed tiles. To achieve tessellation, both tile types must be the same size. The design method is based upon an analytic formulation, and was applied to the realization of a 20-way power divider operating at 1 GHz that uses surface-mount lumped components. The resulting divider was 50 mm by 50 mm. Over a 10% bandwidth, the measured insertion loss was less than 1.3 dB, the measured couplings track within plusmn1 dB and plusmn6deg , and the measured input port return loss and isolation was greater than 20 dB. This level of isolation was achieved without isolation resistors. Equal in-phase power division to output ports on the square-shaped periphery allows compact integration with other planar circuit modules in a combined amplifier. The design method can be extended to N-way power division where N is an odd integer multiple of 4.     

Synthesis of Broad-Band 3-dB Hybrids Based on the 2-Way Power Divider

The synthesis of broad-band 2-way Wilkinson hybrids is well known. The even- and odd-mode analysis results in two equivalent circuits where the synthesis of the odd mode is done by computer optimization. This paper shows an exact synthesis of 2-way Wilkinson power dividers having one isolation resistor, but an arbitrary number of quarter-wave transformers. A large number of circuits have been synthesized with up to 6 quarter-wave transformers. The 2-way Wilkinson hybrid can be extended to a 4-port component. This 4-port component can operate as a 180° or 90° 3-dB hybrid depending on the input port. The hybrid has a high directivity independent of frequency when used as a 180° hybrid. Experimental results are given for a 2-way divider and a 3-dB hybrid built in microstrip with a center frequency of 5 GHz.     

A 24 GHz Amplitude Monopulse Comparator in 0.13 $mu$m CMOS

This letter presents the design and implementation of a wideband 24 GHz amplitude monopulse comparator in 0.13 $mu$m CMOS technology. The circuit results in 9.6 dB gain in the sum channel at 24 GHz with a 3-dB bandwidth of 23.0–25.2 GHz, and a sum/difference ratio of $> 25$ dB at 20–26 GHz. The measured input P1 dB is ${-}14.4$ dBm at 24 GHz. The chip is only 0.55$,times,$ 0.50 mm$^{2}$ (without pads) and consumes 44 mA from a 1.5 V supply, including the input active baluns and the differential to single-ended output stages (28 mA without the input and output stages). To our knowledge, this is the first demonstration of a high performance mm-wave CMOS monopulse comparator RFIC.      

A Y To /spl Delta/ Transformation of a Three-Way Hybrid Junction

A three-way power divider/summer in the Wilkinson configuration can be symmetrically fabricated in stripline if the Y resistive balancing network is replaced by a /spl Delta/ resistive network. Port-to-port isolation in a stripline circuit at 2 GHz exceeded 27 dB; loss was below 0.15 dB.     

A 22–29-GHz UWB Pulse-Radar Receiver Front-End in 0.18-$mu{hbox{m}}$ CMOS

The design of a CMOS 22–29-GHz pulse-radar receiver (RX) front-end for ultra-wideband automotive radar sensors is presented. The chip includes a low-noise amplifier, in-phase/quadrature mixers, a quadrature voltage-controlled oscillator (QVCO), pulse formers, and baseband variable-gain amplifiers. Fabricated in a 0.18-$mu{hbox{m}}$ CMOS process, the RX front-end chip occupies a die area of 3 ${hbox{mm}}^{2}$. On-wafer measurements show a conversion gain of 35–38.1 dB, a noise figure of 5.5–7.4 dB, and an input return loss less than $-$14.5 dB in the 22–29-GHz automotive radar band. The phase noise of the constituent QVCO is $-$107 dBc/Hz at 1-MHz offset from a center frequency of 26.5 GHz. The total dc power dissipation of the RX including output buffers is 131 mW.      

A 40-GHz Low-Noise Amplifier With a Positive-Feedback Network in 0.18-$mu{hbox{m}}$ CMOS

A novel circuit topology for a CMOS millimeter-wave low-noise amplifier (LNA) is presented in this paper. By adopting a positive-feedback network at the common-gate transistor of the input cascode stage, the small-signal gain can be effectively boosted, facilitating circuit operations at the higher frequency bands. In addition, $LC$ ladders are utilized as the inter-stage matching for the cascaded amplifiers such that an enhanced bandwidth can be achieved. Using a standard 0.18-$mu{hbox{m}}$ CMOS process, the proposed LNA is implemented for demonstration. At the center frequency of 40 GHz, the fabricated circuit exhibits a gain of 15 dB and a noise figure of 7.5 dB, while the return losses are better than 10 dB within the 3-dB bandwidth of 4 GHz. Operated at a 1.8-V supply, the LNA consumes a dc power of 36 mW.      

Miniaturized Microstrip Wilkinson Power Divider With Harmonic Suppression

A microstrip Wilkinson power divider with harmonic suppression and size reduction is presented in this letter. The proposed power divider not only effectively reduces its occupied area to 36.5% of the conventional design at 2.65 GHz but also has higher order harmonics suppression. From the measured results, a 29 dB suppression for the third harmonic and a 34 dB suppression for the fifth harmonic are achieved while maintaining the characteristics of a conventional Wilkinson power divider. Based on a 15 dB return-loss criteria, the measured fractional bandwidth is 48%. At an operation frequency of 2.65 GHz, the insertion losses are better than 3.4 dB, the return loss is 27 dB, and the isolation is better than 22 dB.      

Design of Low-Profile Millimeter-Wave Substrate Integrated Waveguide Power Divider/Combiner

A low-profile millimeter-wave substrate integrated waveguide (SIW) power divider/combiner is presented in this paper. The simplified model of this compact SIW power dividing/combining structure has been developed. Analysis based on equivalent circuits gives the design formula for perfect power dividing/combining. In order to verify the validity of the design method, a four-way SIW power divider/combiner circuit operating at Ka band is designed, fabricated and measured. Good agreement between simulated and measured results is found for the proposed passive power divider/combiner. Experiments on the four-way passive divider/combiner back-to-back design demonstrate a minimum overall insertion loss of 1.5 dB at 31.1 GHz, corresponding to a power-combining efficiency of 84%. The measured 10-dB return loss bandwidth is demonstrated to be 2.2 GHz, and its 0.5-dB bandwidth was 2 GHz.     

用于微波组件的LTCC Wilkinson功分器设计

基于LTCC工艺,设计了一种可用于微波组件的新型三维Wilkinson功分器,设计指标为:工作频带介于2.2～2.7GHz,插入损耗<0.5 dB,隔离度>20 dB,驻波比<1.30.使用HFSS软件为该功分器建立了模型并进行了仿真计算.仿真结果表明:该功分器在工作频带内的插入损耗<0.3 dB,隔离度>20dB,驻...     

A Compact Two-dimensional Power Divider for a Dielectric Rod Antenna Array Based on Multimode Interference

In this work, multimode interference is investigated for the design of a two-dimensional fully dielectric power divider, well suited for the usage of dielectric waveguides. Most important, power division is achieved in a single device without the need of cascading multiple dividers. This allows to design a very compact and lightweight power divider, well applicable for dielectric rod antenna arrays. As a proof of concept for the used technique, a 16-way power divider with 4 × 4 output ports, made out of Rexolite, is realized, working in a frequency range between 90 and 105 GHz. For the S-parameter measurements, a special measurement setup, including a modular pin probe technique as well as radiation taper for waveguide termination, is proposed. The measurements are in good agreement with the simulations with a power split of ??15 dB for all output ports within the desired frequency range. This is equal to an additional insertion loss of 3 dB. To demonstrate the usability for antenna arrays, a fully dielectric rod antenna array is realized based on the proposed power divider. With this array, a gain of 22.5 dBi at 97.5 GHz was achieved.     

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$^{circ}$.