Showing papers on "Balun published in 2023"

Base Station MIMO Antenna in 1 × 6 Array Configurations with Reflector Design for Sub-6 GHz 5G Applications

Abstract: In this article, a base station array antenna in 1 × 6 configuration is proposed for sub-6GHz 5G applications. Analyses have been performed on two orthogonally arranged dipole strips, a balun with various feeding schemes, and a reflector with different side walls. At the balanced feed position, aluminum is used to connect the feeding balun and the dipole through a hole. A single crossed antenna element of size 66 × 66 × 78 mm3 is fabricated using an FR-4 substrate with a dielectric constant of 4.4, 1.6 mm thickness, and an operating frequency band from 3.2 to 5.22 GHz. The radiating element provides a stable and high gain of 11–18 dB using reflectors with sidewalls. The proposed element is simulated, and its electrical downward tilt is investigated for a 1 × 6 array arrangement with dimensions of 642 mm × 112 mm × 90 mm. Various radiation performance parameters are measured, such as gain, FBR (>26 dB), HPBW, and XPD (>11.5 dB) at 60° in the H-plane. A reflection coefficient of less than −15 dB and port-to-port isolation of greater than 27 dB are achieved. Simulation and measurement of radiation patterns are performed for the operating frequencies of 3.2, 4.2, and 5.2 GHz.

A Wideband Base Station Antenna Loaded with Bow-Tie-Like Parasitic Elements

Abstract: A ±45° dual-polarization wideband antenna for 5G base station application is proposed using cross dipoles, bow-tie-like parasitic elements and baluns. The antenna is modeled, simulated and optimized to get an optimal size of 115mm × 115mm × 27.8mm. The antenna has a -10dB bandwidth of 2.24GHz-3.75GHz and a fractional bandwidth of 50.4% and its isolation of two orthogonal ports is exceed than 25dB over the operating frequency band. The dual-polarized antenna is fabricated and measured to get a result that it has wide bandwidth, good directional radiation patterns, and high peak gain of 8.1±1.1dBi, making it suitable for 5G base station applications.

A Miniaturized Dual-Band Dual-Polarized Base Station Antenna Loaded with Duplex Baluns

Abstract: A novel miniaturized dual-band and dual-polarized base station antenna loaded with duplex baluns is proposed in this letter. The duplex balun consists of a lower-band filter structure (LFS) and an upper-band filter structure (UFS). The LFS contains a stepped-impedance filter, an open-circuited stub, and an impedance matching section. The UFS contains a highpass filter and an impedance matching section. The proposed antenna has two independent current paths, which enables it to operate in dual bands, and the two paths are bent to achieve its small overall size. By miniaturizing the antenna and loading LFS&UFS, the operating bands of 1.71-2.17 GHz and 3.22-3.7 GHz, the compact size of $0.24 \times 0.24 \times 0.18\lambda _{LL}^3$ (λ _LL is the wavelength at the lowest frequency of the lower band), the lower coupling coefficients(<-20dB), the normal in-band radiation characteristics, and good out-of-band suppression characteristics(>20dB at the lower-band ports as well as >23dB at the upper-band ports) are obtained. It represents an excellent scheme for 5G applications.

A 35 dBm P_SAT and 41% PAE GaAs Power Amplifier With Series Distributed-Balun

Abstract: This brief presents a high-power Sub-6 GHz two-way differential power amplifier (PA) with a series distributed-balun output network in $0.5{\mu }\text{m}$ GaAs pHEMT process. The proposed series distributed-balun output network consists of two coupled-line-based distributed-baluns connected in series to achieve low-loss matching and power combining. The general three-port distributed-balun unit and its extended two-way series distributed-balun have been theoretically analyzed in detail. In addition, the multi-layer transformer structure is introduced to enhance the coupling factor of the inter-stage matching network. The measurement results of this three-stage PA demonstrate a peak gain of 32.6dB, with 3-dB bandwidth (BW−3dB) of 4.2-6 GHz. The saturated output power (Psat) is 34–35 dBm covers 4.8-6 GHz, and the peak power-added efficiency (PAE) is 41%. The measured root mean square error vector magnitude (EVMrms) with 160MHz of 64-QAM/256-QAM is 2.4%/1.93% with 28.7/26.5 dBm average output power (Pave) and −36.8/−38.7 dBc adjacent channel leakage ratio (ACLR) without digital pre-distortion (DPD).

A 28 GHz and 38 GHz Dual-Band Up-Conversion Mixer for 5G Applications in 22 nm FD-SOI CMOS

Abstract: This paper investigates a dual-band direct up-conversion mixer operating at 5G millimeter-wave (mmW) bands. To prove the concept, the mixer is implemented in a 22nm FDSOI technology. A Gilbert cell was applied for the mixer core to achieve a high local oscillator signal (LO) suppression. An active balun was integrated on-chip to manage and optimize the LO phase- and magnitude-mismatch. Dual-band and broadband matching networks enable dual-band operation. The mixer has a total power consumption of 38mW including the LO active balun, mixer core and RF output buffer. The measurements show a conversion gain of −2.6 dB and −1 dB and a 1-dB output compression point ($\mathrm{oP}_{1\mathrm{d}\mathrm{B}}$) of −2.5 dBm and −0.6 dBm at 28 GHz and 38 GHz bands, respectively. The core area of the design is 0.24 mm ² . The mixer compares well against other designs operating at 5GmmW bands by showing one of the highest $\mathrm{oP}_{1\mathrm{d}\mathrm{B}}$, a comparable conversion gain and power consumption. To the best knowledge of the authors, this is the first 5G dual-band up-conversion mixer from technology node 22nm and below.

A 16-21 GHz Double-Balanced Gilbert Upconversion Mixer with Low in-Band Spurious Using 0.25μm GaAs pHEMT Technology

Abstract: This paper presents a 16-21 GHz double-balanced Gilbert upconversion mixer with low RF in-band spurious implemented in 0.25μm GaAs pHEMT technology. To achieve good balance performance, a Marchand balun with spiral structure is set at the LO port, CS-CG baluns with low unbalanced and good matching performances are designed and optimized to set at IF and RF ports. Gilbert mixer is improved by adding charge injection part and LR load to realize high in-band spurious target as well as moderate gain and linearity. The full mixer with baluns is integrated on MMIC chip with an area of 2.7mm×1.76mm. RF in-band suppression of the mixer is more than 40dB over the frequency of 16-21GHz. The mixer has a conversion gain of more than 7dB and OP1dB of -8dBm, OIIP3 of 4dBm when LO power is 5dBm.

Divide-by-4 Injection-Locked Frequency Divider Using Dual Linear Mixer Technique

Abstract: We demonstrate a K-band (18–27 GHz) divide-by-4 injection-locked frequency-divider (ILFD4) in 90 nm CMOS. A wideband balun is used for converting the single-ended injection signal to differential injected signals. Divide-by-4 is attained using dual linear mixer technique, i.e., dual divide-by-2. The first quadrature-phase (I/Q-phase) divide-by-2 is performed by the direct-injection to the differential switch transistors. The second divide-by-2 is carried out by the tail-injection to the I/Q-phase cross-connected four-stage differential ring oscillators. Due to the inherent divide-by-4 feature of the dual linear mixer, strong differential-I/Q divide-by-4 outputs are obtained. In addition to the first-stage frequency divider of a K-band phase-locked loop, the circuit can also be used to provide the required differential-I/Q LO signals (for I/Q modulation/demodulation) of a 28 GHz 5G transceiver. The ILFD4 consumes 7.2 mW and achieves locking range of 48.4% (12.2-20 GHz) and figure-of-merit (FOM) of 6.72 mW ⁻¹ , one of the best results ever reported for CMOS ILFD4s with similar operation frequency.

Low imbalanced fully matched active baluns design for 21GHz upconversion mixer

Abstract: Low imbalanced and fully matched active baluns have been designed for 21GHz up-conversion Gilbert mixer’s ports. It consists of a common-gate FET and a common-source FET with input and output matching networks. The balun has been realized in 0.25μm GaAs pHEMT process. Simulation shows that the phase error of LO balun could be controlled within 2 degrees over the frequency of 3-6GHz, and the phase error of IF balun could be controlled within 3 degrees over the frequency of 16-18GHz.All ports are matched at the impendence of 50Ω for mixer use. The inhibition of the Gilbert mixer using proposed active baluns is more than 40dBc.

A Compact Wideband Dual-Polarized Dipole Antenna with High-Isolation

Abstract: This paper presents a compact wideband dual-polarized dipole with high isolation. The proposed antenna makes use of two T-shaped orthogonal oscillators to realize the dual-polarization radiation. The wideband impedance matching is realized by the coaxial slotted balun. To reduce the size of the designed dipole, the arms of the oscillators are bent down. By optimizing various design parameters affecting antenna performances, the simulation results show that the relative impedance bandwidths of two ports are 32.1% (11.65GHz~16.1GHz) and 31.3% (11.45GHz~15.7GHz), respectively, and the port isolation is more than 45 dB, which indicates that the proposed dipole antenna has good dual-polarized radiation characteristics.

Design of Miniaturized Multilayer Ceramic Chip Balun Using LTCC

Abstract: 본 논문에서는 광대역 특성을 갖는 머천드 발룬을 소형화 시키기 위해 다층 구조에 적합한 회로를 제작하였다. 또한, 제품의 제작성을 용이하게 하기 위해 동시소성 세라믹 구조를 활용하였다. 그리고 소형화를 구현하기 위해 적층형 결합 선로 구조를 구현하였으며, 구조의 전기적인 특성을 확인 하기 위해 3차원 구조 시뮬레이터인 Ansys사의 HFSS를 이용하여 특성을 확인 하였고, 8층 구조를 구현한 적층형 결합선로 제작 기술을 이용하여 1608 ( 1.6 x 0.8 x 0.69 mm3 )크기의 소형화된 칩 발룬을 제작 하였다. 또한, 동시 소성하는 세라믹의 온도를 약900도 근처에서 소성할 수 있는 저온 소성법을 활용하여 도체의 특성을 은(silver)를 활용하여 제작함으로 손실의 최소화를 이루었다. 제작된 칩 발룬은 5G 주파수 대역인 동작 주파수 3.5~4.5GHz 대역으로 설정 하였으며, 제작 결과 삽입 손실은 1.5dB 이하이며 반사손실은 20dB 이하를 나타내었고, 양 출력단의 측정됨 위상차는 180°±5° 범위 내의 양호한 특성을 얻을 수 있었다. 이는 시뮬레이션을 통해 구한 결과와 매우 우수한 일치를 보였다.

DC-Coupled Ultra Broadband Differential to Single-Ended Active Balun in 130-nm SiGe BiCMOS Technology

Abstract: The dc-coupled (DCC) broadband operation is a fundamental requirement in many applications, especially in optical communication systems. However, circuits allowing differential to single-ended conversion in a DCC fashion are very rare to be found in the literature. In this letter, a novel differential to single-ended ultrabroadband DCC balun in a 130-nm SiGe BiCMOS technology featuring $f_{t}/f_{\max }$ of 300/500 GHz is presented. A circuit analysis and a performance comparison between the proposed balun and two other configurations which are commonly used to convert a differential signal to a single-ended one is carried out. The design of the mentioned balun is described focusing on the trade-offs between gain, bandwidth (BW) and linearity. Measurement results show how the presented topology can achieve a low-frequency power gain of −7 dB and a 1 dB BW of 80 GHz, along with a total harmonic distortion (THD) of 7%.

A Wideband Balun Filter Based on Folded Ring Slotline Resonator and Dual-Feedback Stubs With &gt;17.8 <i>f</i> ₀ Stopband Rejection

Abstract: This brief proposes a wideband balun filter with ultrawide stopband utilizing a shunt slotline coupled with a folded ring slotline resonator (FRSR) and dual-feedback stubs (DFS). Utilizing the FRSR, there are four transmission poles (TPs) within the passband and ten transmission zeros (TZs) in the range of < 20 GHz generated, which contribute to large bandwidth, high selectivity, and >10-dB harmonic suppression. In addition, the two additional TZs generated by the DFS can improve the harmonic suppression to >18 dB. In the meantime, the folded slotline design effectively reduces the size of the proposed balun filter to 33.2% of the conventional round slotline ring. The fabricated balun filter demonstrates a 111% fractional bandwidth (FBW) centering around $f_{0}$ of 2.25 GHz, a measured stopband up to 40 GHz (17.8 $f_{0}$ ) with a minimum rejection level of 18 dB, and a shape factor of 1.3. To the best of the authors’ knowledge, both the fractional bandwidth and stopband range achieved by the balun filter are among the best.

A low‐profile wide‐angle scanning ultrawideband tightly coupled dipole array without any wide‐angle impedance matching layer

Abstract: The present is a low-profile, wide-angle scanning, ultrawideband, tightly coupled dipole array that lacks a wide-angle impedance matching layer and lossy materials. Impedance matching will deteriorate at the lower end of the operating bandwidth due to the influence of the ground plane. A well-designed perforated balun is used to achieve better impedance matching. Moreover, parasitic metallic strips are attached to the dipole's side to add additional reactive components. According to the results of simulations, the impedance bandwidth of the array, which ranges from 0.67 to 2.83 GHz, and its wide-angle scanning capability, which scans 75° in the E-plane and 45° in the H-plane, both achieve good performance when the voltage standing wave ratio is less than 3. The profile of the array is only 0.0581λlow above the ground plane, where λlow is the wavelength at the lowest operating frequency. The proposed array's simulated results are validated by fabricating and measuring an 8 × 8 prototype array.

A 130-GHz Low-Area Power Amplifier in 40-nm CMOS

Abstract: This paper presents a 130 GHz differential common-source architecture power amplifier using a 40-nm CMOS process. To ensure proper matching between the stages, except for the output, a transformer was used to achieve conjugate matching. For the output, a balun was used to match it to the maximum output load impedance. On-wafer tests showed that the maximum gain of the amplifier was 22.5 dB at 130 GHz, the 3-dB bandwidth was 15 GHz, and the output saturation power was 7.7 dBm. At a supply voltage of 1 V, the power consumption was 81 mW, and PAE was 7.1 % at a saturated output power. The chip area, excluding the pads, was 388 μm×168 μm.

Active Balun Design for Next-Generation Telecom Satellite Frequency Converters

Abstract: In this work, we describe the complete design flow of a 1.3–3.3-GHz active balun, exploited to generate a high-voltage swing differential local oscillator (LO) signal driving a highly linear doubly balanced resistive ring mixer. Both the LO active balun and the mixer are integrated into a Ku-band single chip monolithic microwave integrated circuits (MMIC) downconverter for the state-of-the-art telecom satellites. System performance has been maximized designing the different circuits by a holistic approach, which considers a non 50- $\Omega $ environment. The experimental validation is carried out by means of an ad hoc time-domain load–pull test bench and shows that the LO active balun provides two quasi-sinusoidal, 180° out-phased, signals with 2.4-V peak-to-peak voltage to the input ports of the mixer over a very high-impedance loading condition.

Broadband Printed Dipole Array Antennas

Abstract: Design, simulation, and measurement of printed dipole array antennas are presented. The dipole element is fed by a log-periodic microstrip balun. The balun converts the unbalanced microstrip line into a balanced two-wire line feeding the dipole. Two-element and four-element dipole arrays are designed by using Wilkinson power divider parallel feeding networks. The arrays are designed using an inexpensive FR4 dielectric material. The height of the dielectric substrate is 1.6mm and its dielectric constant is 4.5. The proposed antennas are simulated using CST MWS electromagnetic simulator. The simulated impedance bandwidths are 27.5%, 29.5%, and 28.6% whereas the realized gains are 4.2dB, 7.2 dB, and 9.7dB for the single element, two-element, and four-element designs respectively. The two-element array has been manufactured and tested. The simulated results agree well with the measured ones. The obtained bandwidths are 29.5% and 27.9% from simulation and measurement respectively. The centre frequency of the measurement result is slightly shifted up towards 2.15GHz. This is mainly due to the dielectric constant which is not well-defined and can take any value from 4 to 5.

An Ultrawideband Dual-Polarized Phased Array Antenna for Sub-3–GHz 5G Applications With a High Polarization Isolation

Abstract: A dual-polarized ultrawideband (UWB) phased array antenna with a wide scanning range and high isolation polarization characteristics is presented in this article. A tightly coupled dipole with an etched slot is proposed as the element antenna, which has a low active input impedance in a wideband and a wide scanning range. Thus, a simple feed strategy without requiring additional external matching networks and baluns could be adopted for the designed scheme. To obtain a large polarization isolation, a capacitively loaded cross-shaped metallic wall (CSMW) is proposed. It is also helpful to improve the in-band matching by mitigating the bandwidth-limiting loop mode at lower frequencies and removing the undesirable common-mode resonance. As a demonstration, an array is designed with a 4.1:1 bandwidth (0.69–2.88 GHz) and an active VSWR < 3.4 while scanning up to ±45° in the E-, H-, and D-planes. Its polarization isolation is better than 45 dB at the broadside and 35 dB within most of the bandwidth when scanning to ±45° in the E-/H-planes. Its cross-polarization level is more than 51 dB at broadside and 40 dB in scanning up to ±45° in the E- and H-planes. A dual-polarized $8 \times $ 8 array prototype (64 ports per polarization) is manufactured and evaluated. Results from the experiment demonstrate good agreement between the measurement and design. The designed antenna is scalable and has a high polarization isolation, a wide scanning range, an ultrawide bandwidth, and a low cost.

Novel Unbalanced-to-Balanced Quad-Channel Diplexer With Controllable Bandwidth and High Isolation

Abstract: A novel unbalanced-to-balanced (UBTB) quad- channel diplexer consisting of two balun filters sharing a common single-ended microstrip feeder is proposed. By loading a stepped-impedance quad-mode resonator (SIQMR) into the balun filter, not only each mode can be flexibly adjusted, but also the size of the circuit can be reduced. In addition, motivated by the internal hybrid coupling, two adjacent modes are utilized to form a passband filter with a transmission zero. On the basis of which, two channels with flexibly adjustable bandwidth and good frequency selectivity are implemented on Rx or Tx path. Finally, a U-shaped microstrip slot-line structure is utilized as the balanced port to achieve good common-mode (CM) suppression. To verify the proposed diplexer, a quad-channel prototype is designed, fabricated and tested. Measured results of the fabricated circuit agree well with the simulated ones.

A High-Efficiency <i>W</i>-Band Frequency Quadrupler With Current-Reusing Stacked Push–Push Stages

Abstract: This letter presents a $W$ -band frequency quadrupler with current-reusing stacked push–push doubler (PPD) stages, implemented in a 180-nm SiGe BiCMOS process. A series balun is used between two PPDs to generate differential signals for the second PPD stage, while also allowing half of the second stage’s current to be reused in the first doubler stage, thereby improving efficiency. The circuit exhibits a compelling output power, peak conversion gain, bandwidth, harmonic rejection, and efficiency for a quadrupler in this frequency range across a 3-dB bandwidth of 76–94 GHz. The quadrupler achieves a peak conversion gain of 13.5 dB, a peak output power of 8.7 dBm, and a maximum dc-to-RF efficiency of 6.4%.

Dual-Band Filtering Balun Using Dual-Mode Resonators

Abstract: In this paper, a compact dual-band bandpass filter (BPF) and its balun filter are proposed. Initially, a dual-band bandpass filter is designed, and later it is extended to design a balun filter. The design includes one pair of square open loop resonators loaded with an open-circuited stub to obtain dual-band filtering properties and enhance matching. The properties of the balun filter and the dual-band bandpass filter are investigated. The simulation results of the proposed balun bandpass filter (BPF) show effective filtering at 2.4 GHz and 4.32 GHz as the center frequencies, which can be suitable for WLAN applications. The output ports of the Balun filter show an exact 180° phase difference, and it has a great amplitude imbalance with values of about 1.03 dB and 0.61 dB, respectively.

A 12.4–32 GHz CMOS Down-Conversion Mixer for 28 GHz 5G New Radio (NR)

Abstract: We report a low voltage (VDD) and power (PDC) 12.4–32 GHz CMOS down-conversion mixer with high conversion gain (CG) for 28 GHz 5G communications. A quarter-wavelength (λ/4) transmission line (TL) and a coupling capacitor (Cc), named the λ/4-TL-C-based coupler, is proposed. This is the way to attain low-VDD, independent RF transconductance (gm)-stage bias, harmonic suppression, and near perfect coupling from the RF gm stage to the LO switch transistors. The body-self-forward-bias (BSFB) technique, i.e., connection of the gm-stage transistors’ body to drain via a large body resistance, is used for threshold voltage (Vth) and VDD reduction and substrate leakage suppression. CG and noise figure (NF) enhancement at the same or even a lower PDC is achieved because lower VDD and higher gm (due to larger bias current) are used. To facilitate the RF measurement, a compact Wilkinson-power-divider-based balun with small-phase deviation and amplitude imbalance is included at RF and LO inputs. The mixer consumes 6.5 mW and achieves a CG of 14.4 ± 1.5 dB for 12.4–32 GHz (i.e., 3 dB bandwidth (f3dB) of 19.6 GHz), a lowest noise figure (NFmin) of 7 dB, and figure-of-merit (FOM) of 0.023, which is one of the best results ever reported for millimeter-wave (mm-wave) down-conversion mixers with an f3dB larger than 10 GHz and PDC lower than 10 mW.

Analysis and Design of Novel 1800 Hybrid for U-Band Monolithic Subharmonic Mixer in 0.15-μm GaAs pHEMT Technology

Abstract: In this brief, a novel reduced-size 1800 hybrid is presented to implement a U-band subharmonic mixer (SHM) via a 0.15-μm GaAs pHEMT process. The isolations between Σ-port and -port of the proposed 1800 hybrid are significantly enhanced by two structures: one is a compact multiconductor edge-coupled line balun with artificial transmission line and the other is an in-phase power divider composed of λLO/4 coupled line. As a proof-of-principle demonstration, a single balanced SHM with an antiparallel diode pair configuration is designed and fabricated, which exhibits a conversion gain of -12.25 dB 1 1.55 dB within the operating RF frequency of 40 to 60 GHz under 14 dBm LO pumping power. The improved isolations of LO-to-RF and 2LO-to-RF are 33 to 47 dB and 44 to 57 dB, respectively. The measured results surpass previously reported performance of SHMs.

Efficient Hierarchical mm-Wave System Synthesis with Embedded Accurate Transformer and Balun Machine Learning Models

Abstract: Integrated circuit design in millimeter-wave (mm- Wave) bands is exceptionally complex and dependent on costly electromagnetic (EM) simulations. Therefore, in the past few years, a growing interest has emerged in developing novel optimization-based methodologies for the automatic design of mm- Wave circuits. However, current approaches lack scalability when the circuit/system complexity increases. Besides, many also depend on EM simulators, which degrade their efficiency. This work resorts to hierarchical system partitioning and bottom-up design approaches, where a precise machine learning model - composed of hundreds of seamlessly integrated sub-models that guarantee high accuracy (validated against EM simulations and measurements) up to 200GHz - is embedded to design passive components, e.g., transformers and baluns. The model generates optimal design surfaces to be fed to the hierarchical levels above or acts as a performance estimator. With the proposed scheme, it is possible to remove the dependency of EM simulations during optimization. The proposed mixed-optimal-surface, performance estimator, and simulation-based bottom-up multiobjective optimization (MOO) are used to fully design aKa-band mm- Wave transmitter from the device up to the system level in 65-nm CMOS for state-of-the-art specifications.

Design of a Wideband Balun Using IPD Technology for Compensating the Frequency Dependency

Abstract: In this paper, we propose a wideband balun using integrated passive device (IPD) technology. The proposed circuit is designed to compensate for the magnitude deviations by differentiating the magnitude S-parameter and calculating the lumped component value when the derivative value is zero. For a smaller size, the proposed circuit is implemented using IPD technology, and the fabricated circuit’s size is 2.4 mm × 1.02 mm. The magnitude of the measurement results has 3.5 ± 0.3 dB deviations from 2.8–4.58 GHz, and the phase difference has 180° ± 10° from 2.8–5 GHz at the center frequency of 3.6 GHz. Therefore, the measurement results show that the theory of the proposed circuit is well matched compared with the measurement results for smaller sizes, wideband magnitude, and phase characteristics.

An 18–50-GHz Double-Balanced GaAs Mixer Using Novel Ultrawideband Balun

Abstract: In this letter, a novel multiconductor coupled line (MCL) balun is presented for the implementation of a wideband double balanced mixer (DBM). The proposed balun utilizes an artificial transmission line (ATL) (composed of periodical shunt stubs), and manages to shorten the length by 65.1% compared with the three-line balun. Besides, in order to provide a point for intermediate frequency (IF) extraction, two sections of coupled lines are exclusively added behind local oscillator (LO) balun. And this structure also transmits LO signals to the diodes for mixing. Through the aforementioned operations, a compact balun and an 18–50 GHz mixer in 0.15- $\mu$ m GaAs pseudomorphic high electron mobility transistor (p-HEMT) process are designed. The measured results show that within the operation frequency, the phase and amplitude difference of the balun are lower than 3.5 $^{\circ}$ and 1.1 dB, respectively. The mixer dB conversion loss (CL) and 33 dB LO-to-RF isolation under 15 dBm LO power. The monolithic microwave integrated circuit (MMIC) area is 0.96 $\times$ 1.68 mm $^{2}$ , including all pads.

Analysis and Design of Broadband Balance-Compensated Transformer Baluns for Silicon-Based Millimeter-Wave Circuits

Abstract: This paper presents the analysis and design of broadband balance-compensated transformer baluns, suitable for silicon-based millimeter-wave (mm-wave) circuits requiring broadband high-quality balanced-unbalanced conversion. By introducing a mode-dependent lumped-element transformer model, a general center-tap-based balance-compensation method is proposed for transformer baluns, with two practical broadband compensation techniques derived. Several critical issues regarding the practical design of broadband balance-compensated transformer baluns are also discussed, including the parasitic effects in balance compensation, the consideration of windings’ turn number, and the balun design for impedance matching. As a proof-of-concept, three broadband balance-compensated transformer baluns, operating at different frequencies, are employed in a D-band frequency sextupler in mode = text, reset-text-series = false22FD-SOI CMOS. The fabricated sextupler demonstrates a 5.1-dBm peak output power and mode = text, reset-text-series = false8.49% peak DC-RF efficiency at mode = text, reset-text-series = false145.5, and presents a 3-dB peak output power bandwidth ranging from mode = text,reset-text-series = false, range-units = single127162with more than 37-dBc harmonic rejection ratio (HRR).

A Coupler Balun Load-Modulated Power Amplifier With Extremely Wide Bandwidth

Abstract: Next-generation millimeter-wave (mm-Wave) power amplifiers (PAs) need to support multistandard communication systems with wide bandwidth, complex modulation, and high energy efficiency. Most existing mm-Wave PA architectures with power backoff (PBO) efficiency enhancement, such as Doherty and outphasing PAs, typically only support limited carrier bandwidth. In this work, we propose and demonstrate that a 180° coupler balun structure can serve as an extremely wideband active load modulation network for broadband PBO efficiency enhancement and further realize a coupler balun load-modulated PA (CBMA). Moreover, compared to load-modulated balanced amplifiers (LMBAs), the proposed CBMA supports natural single-ended-to-differential balun conversion, differential power cells, and wideband capacitive neutralization, ideal for integrated mm-Wave PAs. Furthermore, we propose a continuous-mode CBMA operation with role exchanges to attain a nearly 3:1 carrier bandwidth. A prototype CBMA is designed and fabricated in a 45-nm RF CMOS SOI process, which achieves an OP1 dB PAE of 39.9%–20.4% with OP1 dB of over 21.6–18.3 dBm from 26 to 60 GHz. The PA also achieves a 32.8%–13.4% 6-dB PBO (from OP1 dB) efficiency with its best $1.75\times /3.51\times $ efficiency enhancement over an ideal Class-B/-A PA. Using a single-carrier 64-QAM signal with 0.5 GSym/s (3 Gb/s), the PA supports an average $P_{\mathrm {out}}$ of 15.8–11.3 dBm with an average PAE of 27.15%–8.58% with −23-dB rms error vector magnitude (EVM) over 26–60 GHz. The PA also supports 5G NR modulation using 5G new radio (NR) FR2 200-MHz 1-CC 64-QAM signals, achieving 18.22%–6.55% average PAE at 10.72–7.1-dBm average $P_{\mathrm {out}}$ with rms EVM of −23 dB over 26–60 GHz.