新型宽带GCPW射频传输转换

本文提出了一种新型宽带GCPW(Grounded Coplanar Waveguide,地面共面波导)射频传输转换结构,用于解决两个不同平面背靠背式的GCPW射频传输转换。首先将GCPW转换为CPW,宽带共面波导的传输转换是通过金带连接的方式实现传输平面的转换。在工作频率为2GHz—17.5GHz,带宽为15.5GHz的条件下,这种传输转换形式实现了传输损耗小于0.5d B,回波损耗大于16.7d B。这种传输方式较好的解决了较大间距背靠背式GCPW射频信号的传输转换,而且过渡结构简单,尺寸小,工程上容易实现。     

Analysis and Design of Current Probe Transition From Grounded Coplanar to Substrate Integrated Rectangular Waveguides

The transition between a grounded coplanar waveguide (GCPW) and a substrate integrated rectangular waveguide (SIRW) is investigated in this paper. The proposed scheme makes use of a current probe to transfer power between the two dissimilar transmission lines. A computer-aided-design-oriented analytical model is developed in order to optimize the geometrical dimensions of the transition. By using the GCPW instead of the microstrip line to interface the SIRW, substrate thickness can be increased without incurring a penalty due to transmission loss. Therefore, it is possible to achieve higher$Q$components. Experiments at 28 GHz show that an effective bandwidth of 10% can easily be obtained. The insertion loss is less than 0.73 dB over the bandwidth of interest.     

A Novel GCPW to Rectangular Waveguide Transition for 60 GHz Applications

A new type of grounded coplanar waveguide (GCPW) to rectangular waveguide transition in an LTCC multi-layer structure for 60 GHz applications is proposed in this letter. The GCPW and rectangular waveguide are fully integrated on the same substrate, and the ground wall of the rectangular waveguide is made up of a staggered via fence. The transition is accomplished by inserting a bent short stub. We analyze and prove the novel transition structure by applying an equivalent circuit model. Measured results for a single transition show that the insertion loss is 0.345 dB at 59 GHz and the bandwidth is 6.3 GHz. The proposed transition structure with very low loss at a large bandwidth is very suitable for a SiP of 60 GHz WPAN applications.      

Novel coplanar waveguide to slotline transition on high resistivity silicon

Two novel coplanar waveguide (CPW) to slotline transitions have been fabricated and tested on high resistivity silicon. The first transition uses an air bridge to couple RF power from the CPW line to the slotline and has the entire circuit on the top side of the wafer. In the second transition, the grounded CPW (GCPW) line and the slotline are on opposite sides of the wafer and are coupled electromagnetically. The measured average insertion loss and return loss per transition are better than 1.5 and 10 dB, respectively, with a bandwidth greater than 30% at C-band frequencies.<>     

CPW-to-waveguide transition using three-step Chebyshev transformer

A transition structure between a coplanar line and a rectangular waveguide using a three-step Chebyshev transformer is proposed. The structure was designed, manufactured and tested in the X-band. Measurement results show good agreement with the simulation results. A bandwidth of 32% with a return loss better than -20 dB and an insertion loss better than -1 dB over the X-band were obtained.     

SIR结构ACPW滤波器研究

文章提出将SIR谐振器结构应用于非对称共面波导传输线中,设计了一种新型SIR结构非对称共面波导带阻滤波器。通过四个SIR谐振单元在非对称共面波导传输线中级联,有效地改善了滤波器的插损和带宽。结果显示,本滤波器中心频率为1．8GHz,最小插损为0．4dB,相对带宽为33．3％,最大带外抑制为-60dB。具有小体积、低插损、高抑制、宽阻带、易于加工等优点。     

Broadband Transition Between Double-Sided Parallel-Strip Line and Coplanar Waveguide

A broadband transition between double-sided parallel-strip line and coplanar waveguide is proposed in this letter. This design is based on tapered structure and vertical coupling, which doesn't require any via hole. The proposed transition has a simple structure for easy fabrication. Several parameters are studied by simulation to optimize the transition. A demonstration back-to-back transition is fabricated and measured. The experimental results show that the insertion loss of less than 1.4 dB and the return loss of better than -10dB is obtained from 1.3 to 9GHz     

Ultra-wideband (from DC to 110 GHz) CPW to CPS transition

A new ultra-wideband, low-loss and small-size coplanar waveguide (CPW) to coplanar strip (CPS) transition which can be used from DC to 110 GHz is presented. The proposed transition connects CPW with CPS by the reformed air-bridge. Two ground planes of CPW are tied at their ends by a line and the centre of the line is connected to the ground strip of CPS by another line. Owing to the symmetry of the proposed structure, the currents of two ground planes of CPW are combined with the same phase and transferred to the ground strip of CPS. With height of 3 μm, the signal line of CPW passes over two connecting lines and is connected to the signal strip of CPS. For the back-to-back transition structure, insertion loss <1 dB and return loss >15 dB are obtained from 0.5 to 110 GHz     

S-Parameter Extraction on Coupling Between DR and GCPW

This letter presents that coupling characteristics between a cylindrical TE_01delta mode dielectric resonator (DR) and a grounded coplanar waveguide (GCPW) have been examined in terms of S-parameters. The investigation of finite element method simulation (HFSS) agrees well with the measurement results. Unloaded Q values of the DR coupled with three uniform CPWs are compared with those of the DR coupled with microstrip line. The comparison shows that the DR coupled with the GCPW has the highest unloaded Q     

一种新型毫米波集成波导微带转换的分析与设计

提出一种新型集成于单层微带基片的毫米波集成波导微带转换 ,由一圆形微带谐振器、微带共面波导探针组成。利用全波分析软件对该转换器进行了分析计算、优化设计。测试了波导微带转换实物 ,结果表明 ,在Ka波段在 1 GHz频带内 ,该波导微带转换具有较低的插入损耗 ( <0 .4d B)和反射损耗 ( <-1 4d B)。可满足相关毫米波微带集成电路系统的应用要求。     

Coplanar waveguide radial line double stub and application to filter circuits

Coplanar waveguide (CPW) and grounded coplanar waveguide (GCPW) radial line double stub resonators are experimentally characterised with respect to stub radius and sector angle. A simple closed-form design equation, which predicts the resonance radius of the stub, is presented. Use of a double stub resonator as a lowpass filter or as a harmonic suppression filter is demonstrated and design rules are given.<>     

Ultra-Wideband CPW-to-Substrate Integrated Waveguide Transition Using an Elevated-CPW Section

In this letter, an elevated-coplanar waveguide (ECPW) is proposed for an intermediate section of a coplanar waveguide (CPW)-to-substrate integrated waveguide (SIW) transition. The ECPW is used to attain a gradual mode matching and to achieve the consequent wide bandwidth. The measurement results show 70% fractional bandwidth at 10 dB return loss and 0.9 dB insertion loss from 19 to 40 GHz. We expect that the proposed SIW transition plays an important role for the integration of high-Q SIW with CPW circuits, such as millimeter-wave system-in-package (SiP) using SIW circuits.      

Compact CPW-MS-CPW Two-Stage pHEMT Amplifier Compatible With Flip Chip Technique in V-Band Frequencies

The V-band coplanar waveguide (CPW)-microstrip line (MS)-CPW two-stage amplifier with the flip-chip bonding technique is demonstrated using 0.15 mum AlGaAs/InGaAs pseudomorphic high electron mobility transistor technology. The CPW is used at input and output ports for flip-chip assemblies and the MS transmission line is employed in the interstage to reduce chip size. This two-stage amplifier employs transistors as the CPW-MS transition and the MS-CPW transition in the first stage and the second stage, respectively. The CPW-MS-CPW two-stage amplifier has a gain of 14.8 dB, input return loss of 10 dB and output return loss of 22 dB at 53.5 GHz. After the flip-chip bonding, the measured performances have almost the same value.     

Wideband coplanar waveguide RF probe pad to microstrip transitions without via holes

A novel via-less coplanar waveguide (CPW) to microstrip transition is discussed and design rules based on simulations and experimental results are presented. This transition demonstrates a maximum insertion loss of 1 dB over the frequency range from 10 GHz to 40 GHz with a value of 0.4 dB at 20 GHz. This transition could find a variety of applications due to its compatibility with RF systems-on-a chip, low loss performance, low cost and its ease of fabrication.     

Wideband coplanar waveguide-to-rectangular waveguide transition using fin-line taper

This letter introduces a new wideband coplanar waveguide-to-rectangular waveguide transition. The transition uses a uniplanar circuit in line with the waveguide, which eases the design and fabrication. The design does not require airbridges. Simulations and measurements of X-band (8.2-12.4 GHz) transitions based on both a low- and high-permittivity material (/spl epsiv//sub r/= 2.33 and 10.8) show that the transition works fine over the full frequency band. For /spl epsiv//sub r/= 2.33 the measured return and insertion loss of a back-to-back transition are more than 16 dB and less than 0.4dB, respectively. The corresponding values for /spl epsiv//sub r/= 10.8 are more than 10 dB and less than 1.0 dB, respectively, over 90% of the frequency band. The measured insertion loss values indicate losses of less than 0.14 dB and 0.36 dB at the center frequency for a single transition on a substrate with /spl epsiv//sub r/= 2.33 and 10.8, respectively.     

Study on Characteristics of Various RF Transmission Line Structures on PES Substrate for Application to Flexible MMIC

In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone‐type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is 0.318 mm × 0.318 mm, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than –12.9 dB from 5 GHz to 50 GHz and an insertion loss better than –1.13 dB in the same frequency range.     

Gap-coupled patch-type waveguide-to-microstrip transition on single-layer dielectric substrate at V-band

A compact gap-coupled patch-type waveguide-to-microstrip transition at V-band is proposed. It uses the coplanar waveguide feed patch and the gap-coupled parasitic patch antenna radiating into the waveguide to improve the bandwidth. This type of transition has a wide bandwidth (BW=4.7%) more than a single-patch-type transition (BW=1.3%) on a single-layer alumina substrate for -15 dB return loss.     

一个DC-32GHz两位微机械移相器

采用分布式微机械传输线结构实现了两位移相器,并且为了减小传输线负载电容和驱动电压首次提出了用共面波导传输线来驱动微机械桥的结构(共面波导驱动结构).结果显示驱动电压小于20V,20GHz时两位移相器的相移为0°/20.1°/41.9°/68.2°,插入损耗为-1.2dB.在DC到32GHz的范围内相移具有良好的线性,插入损耗小于-1.8dB,反射损耗好于-11dB.实验结果表明了该结构在高介电常数衬底上制造低插损、宽带数字微机械射频移相器的潜力.     

Development of a Broadband Coplanar Waveguide-to-Microstrip Transition With Vias

A transition from coplanar waveguide (CPW)-to- microstrip with vias is often used in wafer-probe measurements. This paper shows how field and impedance matching are used to develop a wideband transition. This paper demonstrates how the presence and placement of the vias affect the bandwidth and alters the impedance of the transition. The measured results on a transition show that a wideband transition with return loss better than 10 dB and an insertion loss less than 1.5 dB up to 36.64 GHz is obtained. The measurements show excellent agreement with simulation. The work presented in this paper provides a better understanding about a CPW-to-microstrip transition with vias as well as design procedures and principles that can be utilized to facilitate the realization of a broadband CPW-to-microstrip transition with vias.      

High-performance filtering power divider based on air-filled substrate integrated waveguide technology

A filtering power divider based on air-filled substrate-integrated waveguide (AFSIW) technology is proposed in this study. The AFSIW structure is used in the proposed filtering power divider for substantially reducing the transmission losses. This structure occupies a large area because of the use of air as a dielectric instead of typical dielectric materials. A filtering power divider provides power division and frequency selectivity simultaneously in a single device. The proposed filtering power divider comprises three AFSIW cavities. The filtering function is achieved using symmetrical inductive posts. The input and output ports of the proposed circuit are realized by directly connecting coaxial lines to the AFSIW cavities. This transition from the coaxial line to the AFSIW cavity eliminates the additional transitions, such as AFSIW-SIW and SIW-conductor-backed coplanar waveguide, applied in existing AFSIW circuits. The proposed power divider with a second-order bandpass filtering response is fabricated and measured at 5.5 GHz. The measurement results show that this circuit has a minimum insertion loss of 1 dB, 3-dB fractional bandwidth of 11.2%, and return loss exceeding 11 dB.