A new wide-band planar balun on a single-layer PCB

A new wide-band microstrip balun implemented on a single-layer printed circuit board (PCB) is presented in this letter. The proposed planar balun consists of a wide-band Wilkinson power divider and a noncoupled-line broad-band 180/spl deg/ phase shifter. To demonstrate the design methodology, one prototype is realized. The new design was simulated and validated by the measurement. Measured results show that 10-dB return loss of the unbalanced port has been achieved across the bandwidth from 1.7 GHz to 3.3 GHz, or 64%. Within the operation band, the measured return losses for both the two balanced ports are better than -10 dB, and the balanced ports isolation is below -1.5 dB. The measured amplitude and phase imbalance between the two balanced ports are within 0.3 dB and /spl plusmn/5/spl deg/, respectively, over the operating frequency band.     

一种加载铁氧体磁环的高功率宽带巴伦

针对高功率天线的差分馈电和阻抗匹配问题,文中提出了一种基于同轴线结构加载铁氧体磁环的宽 带巴伦模型。双同轴线具有阻抗变换功能和较好的功率承载能力,铁氧体磁环改善了巴伦在低频时的输入匹配和 两个输出端口不平衡度。仿真和实测表明,此巴伦在0. 05~1. 24 GHz 内回波损耗低于-10 dB,去除3. 0 dB 系统插损 后单端插入损耗在1. 5 dB 以内,两端输出的相位不平衡度在5°以内,幅度不平衡度在2%以内。通过分析巴伦的电 磁热损耗场、温度场和应力形变场,验证了巴伦在高功率馈电下的工作性能,结果表明此巴伦在工作频带内能够承 受500 W 的功率。     

无线收发前端小型化巴伦的研究

针对射频前端的小型化巴伦展开研究,在理论分析上,从变压器型巴伦的原理出发,将电磁场数值方法和微波网络理论相结合,将标准散射（S）参数和混合散射（S）参数相结合,提出了新颖的巴伦特性的理论研究方法;在实际应用上,利用高阻性硅基集成无源器件（Integrated Passive Device,IPD）技术,经过电磁仿真和优化,设计和制作了基于交叉耦合平面螺旋线结构的小型化变压器型巴伦.巴伦的尺寸仅为1.85 mm×1.6 mm,10 dB单端回波损耗带宽为2.07~2.80 GHz,频带内插入损耗小于0.98 dB,差分对幅度失配小于0.43 dB,相位失配小于3.8°,仿真结果得到了实验验证.     

Compact CMOS Baluns for the 4–10 GHz Band Applications

In this paper, we proposed two baluns, a compact balun and a compact balun with imbalance compensation; both are implemented using the one-poly six-metal (1P6M) 0.18 μ m CMOS process. Both baluns have good performance from 4 to 10 GHz, and consume less silicon area due to their compact structure. The self-resonant frequency is increased by properly selecting metal layer for each spiral winding. The compact balun has a magnitude imbalance of 1 dB and a phase imbalance of 4.6 degree from 4 to 10 GHz. With the imbalance compensation, the balun has a magnitude imbalance of 0.6 dB and a phase imbalance of 1.1 degree from 4–10 GHz. Much better results have been achieved for the compact balun with our proposed imbalance compensation method. Both baluns can be used to perform both single-ended/differential and differential/single-ended conversions in different configurations.     

A DC-21 GHz Low Imbalance Active Balun Using Darlington Cell Technique for High Speed Data Communications

A dc-21 GHz low imbalance active balun using a 2 $mu{rm m}$ InGaP/GaAs HBT process is presented in this letter for high speed data communications. A Darlington cell is adopted to enhance 3 dB bandwidth of the proposed active balun. A feedback capacitor is designed to compensate the phase error between differential output ports caused by the different number of stages. The proposed active balun achieves a broad bandwidth of 21 GHz, an average small signal gain of 2.5 dB, a maximum amplitude imbalance of 1.2 dB, and a phase error of less than 5$^{circ}$. The measured group delays of the balun are lower than 30 ps with low variation. Moreover, an eye diagram with a pseudorandom bit stream of up to 12.5 Gbps is presented. The active balun is appropriate for high speed data communications due to its low imbalance and group delay.      

Passive broadband millimetre-wave uniplanar MMIC balun

A new uniplanar monolithic microwave integrated circuit (MMIC) balun using lumped circuits is presented. The proposed planar balun consists of a wideband Wilkinson power divider and a broadband 180° phase shifter using novel series and parallel LC reflective terminating circuits. To demonstrate the design methodology, a 24?44 GHz MMIC balun was realised as a 1.4 mm _{GaAs chip. The measured return losses for the unbalanced and balanced ports are better than 212, 210 and 27 dB, respectively. The measured amplitude and phase imbalance between the two output ports are less than 0.5 dB and 7°, respectively, and maximum insertion loss is 5 dB.}     

A silicon monolithic spiral transmission line balun withsymmetrical design

In this work, a spiral transmission line balun has been fabricated on a high resistivity silicon substrate. The Marchand-type balun has been designed to have the same physical common ground points for the output transmission lines, which eliminates imbalance due to potential difference at the ground. Return loss is better than 17 dB in the frequency band of 1.6-4.1 GHz, especially 39 dB around 1.9 GHz. The amplitude imbalance is less than 0.3 dB throughout the bandwidth. The phase departure from 180° is less than 20 over the frequency range of 1.6-2.6 GHz. The balun is suitable for MMIC application     

Low-Loss and Broadband Asymmetric Broadside-Coupled Balun for Mixer Design in 0.18-$mu{hbox {m}}$ CMOS Technology

This study presents an asymmetric broadside coupled balun with low-loss broadband characteristics for mixer designs. The correlation between balun impedance and a 3D multilayer CMOS structure are discussed and analyzed. Two asymmetric multilayer meander coupled lines are adopted to implement the baluns. Three balanced mixers that comprise three miniature asymmetric broadside coupled Marchand baluns are implemented to demonstrate the applicability to MOS technology. Both a single and dual balun occupy an area of only 0.06 mm². The balun achieves a measured bandwidth of over 120%, an insertion loss of better than 4.1 dB (3 dB for an ideal balun) at the center frequency, an amplitude imbalance of less than 1 dB, and a phase imbalance of less than 5deg from 10 to 60 GHz. The first demonstrated circuit is a Ku-band mixer, which is implemented with a miniaturized balun to reduce the chip area by 80%. This 17-GHz mixer yields a conversion loss of better than 6.8 dB with a chip size of 0.24 mm². The second circuit is a 15-60-GHz broadband single-balanced mixer, which achieves a conversion loss of better than 15 dB and occupies a chip area of 0.24 mm². A three-conductor miniaturized dual balun is then developed for use in the third mixer. This star mixer incorporates two miniature dual baluns to achieve a conversion loss of better than 15 dB from 27 to 54 GHz, and occupies a chip area of 0.34 mm².     

A 20-GHz low-noise amplifier with active balun in a 0.25-/spl mu/m SiGe BICMOS technology

A 20-GHz low-noise amplifier (LNA) with an active balun fabricated in a 0.25-/spl mu/m SiGe BICMOS (f/sub t/=47 GHz) technology was presented by the authors in 2004. The LNA achieves close to 7 dB of gain and a noise figure of 4.9 dB with all ports simultaneously matched to 50 /spl Omega/ with better than -16 dB of return loss. The amplifier is highly linear with an IP/sub 1dB/ of 0 dBm and IIP/sub 3/ of 9 dBm, while consuming 14 mA of quiescent current from a 3.3-V rail, with temperature-compensated biasing. To the authors' knowledge, the LNA delivers the lowest reported noise figure and highest linearity for a silicon implementation of a combined active balun and LNA at 20 GHz, and is the first implementation of an active balun with an LC degenerated emitter-coupled pair. Here we expand on that work, with an analysis of the balun operation and noise optimization of the design.     

A Highly Compact Active Wideband Balun With Impedance Transformation in SiGe BiCMOS

A new conveyor-based single-ended to differential balun is proposed. Thanks to the quasi-absence of passive components, this is an extremely size-efficient balun (0.036 ). The use of a new impedance-matching technique makes this balun the first transistor-based solution with controllable port impedances. Fabricated in a 0.35-mum SiGe BiCMOS technology with f_T=45 GHz, the balun shows the following performance: wideband impedance matching at all three ports, good balance between the two outputs (better than 3 dB in amplitude and 13deg in phase) over frequency bands extending from 0 to 3 GHz, linear operation for powers up to input powers of -2 dBm, and stability against temperature and process variations.     

Wide-band balun using composite right/left-handed transmission line

A wide-band balun is developed using a composite right/left-handed (CRLH) transmission line (TL) at 2 GHz. It is composed of a Wilkinson power divider and two phase-adjusting transmission lines, namely the CRLH TL and the conventional TL. The input reflection coefficient is better than -10 dB from 1 to 4 GHz. Over the frequency range of 1.24-3.58 GHz, an amplitude imbalance of less than 0.7 dB and a phase error of less than plusmn10deg have been experimentally demonstrated.     

A novel planar dual balun for Doubly Balanced star mixer

A novel planar dual balun for doubly balanced star mixer is presented. The balun consists of two identical Marchand baluns using coupled microstrip lines. It shows the amplitude imbalance within 1.2 dB and the phase imbalance within 180/spl plusmn/1.5/spl deg/ over 1.2 to 2.8 GHz. The star mixer using a pair of the suggested balun has the conversion loss about 6 dB in the band.     

A Broadband Substrate Integrated Waveguide (SIW) Planar Balun

A broadband planar balun is presented in this work that makes use of a substrate integrated waveguide (SIW) technique using a printed circuit board process. The proposed balun structure is able to operate at millimeter wave frequencies and it does not require any tight line coupling sections as frequently used in monolithic microwave integrated circuit balun design. In addition, this balun can be integrated with other planar topologies including nonplanar circuits made of the same substrate for achieving high efficiency. This balun structure consists of a 3 dB SIW power divider and microstrip lines that are placed on both sides of the substrate at balanced ports to obtain an 180deg phase shift. The concept is validated by simulations and measurements. Our measured results suggest that a 10 dB return loss at unbalanced port can easily be achieved across a 42% bandwidth from 19 to 29 GHz. Measured amplitude and phase imbalance between two balanced ports are within 1 dB and plusmn5deg, respectively.     

Spiral transmission-line baluns for RF multichip module packages

We describe a design method and lumped model for a circular spiral transmission-line balun. All lumped values are extracted from the geometric parameters of the balun. From simulation, the design parameters with well predicted characteristics are defined. The balun is fabricated using multi-chip module processing technology, which is suitable for integration in RF packages. Measurements show a wide bandwidth of 1.5-4.1 GHz and excellent balanced outputs. Amplitude imbalance less than 0.5 dB and phase imbalance less than 4° are achieved. The simulation results are compared with the measurement. The model captures all important properties of the balun with reasonably high accuracy     

A complete single-chip GPS receiver with 1.6-V 24-mW radio in 0.18-/spl mu/m CMOS

A compact ultra-broadband MMIC-compatible uniplanar balun has been developed using offset air-gap coupler. The offset air-gap coupler presents tight coupling and low conductor loss, and thus allows the balun to show low loss at mm-wave frequencies. The measured insertion loss was less than 2 dB from 26 to 55 GHz, and amplitude and phase imbalance was less than /spl plusmn/1dB and 5/spl deg/, respectively over a wide frequency range from 27 to 69 GHz.     

Active Quasi-Circulator MMIC Using OTAs

A very compact, active quasi-circulator is proposed and experimentally demonstrated in this work. It consists of an active balun and a current combiner using operational transconductance amplifiers in CMOS. Experimental results show that the insertion loss between the circulation ports is low and all three ports have input reflection coefficients below -10 dB. The chip operates from 1.5 to 2.7 GHz and it outperforms previously known monolithic microwave integrated circuit circulators covering this frequency range in terms of the S₃₁ isolation, standing at -26 dB, as well as physical size: the integrated circuit measures only 0.25 mm² including bonding pads.     

基于左手传输线的宽带巴伦设计

提出了一种基于左手传输线的新型Wilkinson巴伦,该巴伦由一个Wilkinson功分器和两条相位响应相差180°的相移 线构成,它具有结构紧凑和宽频带的特点。采用陶瓷基板薄膜加工工艺,制作了一个工作于C波段的Wilkinson巴伦。最后 测试结果显示：从4GHz到6GHz的频率范围内,输入端反射系数|S11|和输出端隔离|S23|均小于-15dB,两输出端口幅度和相 位不平衡性小于0.3dB和±2°,输出端插入损耗|S21|和|S31|大于-4dB。     

A CMOS Active Balun Using Bond Wire Inductors and a Gain Boosting Technique

An active balun with a single-ended input and a pair of differential outputs is presented for the input stages of differential circuits. The active balun, which is composed of an input resonator and cascaded common-gate amplifiers, was implemented using 0.18-mum CMOS technology and bond wire inductors. A body-source cross-coupled configuration was used to enhance the gain of the active balun. The gain is 9.3 dB at 1.8 GHz, and the phase and the amplitude error are less than 2deg and 1 dB, respectively, in the frequency range of 1 to 2 GHz, even for a P_1dB of -2.7 dBm. The balun consumes 9 mA for 3-V supply voltage.     

Wideband LC balun transformer using coupled LC resonators embedded into organic substrate

In this paper, wideband LC balun using coupled LC resonator has been newly designed, simulated, and fabricated. The proposed balun has a novel scheme which consists of two pairs of coupled embedded LC resonators which share one resonator with each other. The coupled resonators are applied to provide a precise phase difference of 180° and an identical magnitude between two balanced ports and DC isolation characteristic with impedance transformation. Furthermore, proposed resonators have relatively small inductance values which can be easily embedded into the organic package substrate. In order to reduce the size of embedded capacitors, BTO composite high dielectric film was applied to increase their capacitance densities. The measured results of fabricated wideband balun exhibited an insertion loss of 1.8 dB, a return loss of 10 dB, a phase imbalance of 0.5°, and magnitude imbalance of 0.7 dB at frequency bandwidth of 700 MHz ranged from 1.8 to 2.5 GHz, respectively. They agreed well with the simulated ones. The fabricated balun has a relatively small volume of 2 mm×3.5 mm×0.66 mm (height).     

一种多端口器件测量技术

给出了一种用二端口矢量网络分析仪(VNA)对多端口器件进行测量的方法,该方法运用简单的迭代法,减小由于其余端口所接负载的非匹配性引入的误差,易于通过软件实现。利用该方法对三端口器件巴伦进行测量,并将最后结果与三端口VNA测得的结果进行比较。比较结果表明,幅度误差小于0.2dB,相位误差小于3°。该方法在多端口VNA不可获得的情况下,可以应用到多端口器件的精确测量上。