Compact membrane-supported bandpass filter for millimetre-wave applications

The design and testing of a new configuration of micromachined bandpass filter for millimetre-wave applications is presented. The design is based on image parameter representation of identical symmetrical cells connected in cascade. The measurements demonstrate transmission losses lower than 1 dB and very good agreement with the electromagnetic simulations.     

Implementation of millimetre-wave bandpass filter with MMIC technology

This study presents the implementation of a millimetre-wave bandpass filter with conventional MMIC technology. The filter utilises the inductive /spl pi/-network coupling structure to minimise the effect of process variation and achieve the desired circuit characteristics. The filter is very compact in size and can be precisely predicted by a commercial EM simulation tool. A 26 GHz filter prototype is designed and fabricated. The measured passband insertion loss is about 5 dB and the attenuations at the stop bands are all greater than 20 dB.     

Quasiplanar 3 dB hybrid for millimetre-wave integrated circuits

A quasiplanar 3 dB hybrid suitable for integration in millimetre-wave fin-line circuits is presented. The performance of the device is characterised by 0.5 dB insertion loss, less than 0.5 dB imbalance and 20?25 dB isolation over the entire Ka-band (26.5?40 GHz).     

Tunable millimetre-wave ferrite bandpass filter with reduced biasing field

A magnetodynamic resonance mode in a partially metallised ferrite slab is proposed for use as an electronically tunable bandpass filter for the frequency range from 30 to 40 GHz. Unloaded Q-factors of greater 100 (350) and an insertion loss of less than 3 dB at 40 GHz have been observed.     

Thick-film fabrication techniques for millimetre-wave dielectric waveguide integrated circuits

The letter presents the results of an initial study performed in the development of millimetre-wave dielectric waveguide integrated circuits using novel thick-film printing techniques. The measurements of the propagation characteristics of sample lines at 60 GHz demonstrate the feasibility of such an approach and examples of printed components indicate its potential in low-cost high-volume applications.     

Compact wideband bandpass filter using quad mode resonator

This paper presents a compact wideband bandpass filter for TETRA band applications. The proposed filter design is based on a quad mode resonator designed using small rectangular loop loaded with four Stepped Impedance Stubs (SISs) and a short circuit stub. The four modes of the resonator help in generating a wide passband. The use of SISs makes the filter compact. In addition to four transmission poles, the resonator inherently generates a transmission zero above the higher end of passband. Two transmission zeros are generated by the input/output coupling which helps in increasing the selectivity and also for achieving wide stopband. This filter provides a 3 dB fractional bandwidth of 30.33% and maximum insertion loss of 1.3 dB at the center frequency 0.36 GHz with a compact size of 0.125 λ_g × 0.085 λg (4.1 × 2.78 cm²).     

A high-dynamic-range integrated continuous-time bandpass filter

An eighth-order Butterworth bandpass filter, operating at 100 kHz with a quality factor of 14.3, is presented. The filter features an optimized dynamic range, a large tuning range, and a small occupied chip area of 0.25 mm² owing to very simple circuitry. Measurements show a very accurate realization of the desired transfer function, a high dynamic range of 62 dB, and a tuning range from 50 to 200 kHz. It is shown how the dynamic range can be improved to a theoretical maximum if circuit simplicity is sacrificed     

CAD techniques for the electromagnetic design of monolithic millimetre-wave integrated circuits

It is well known that mm-waves have an important role to play in the rapid expansion of mobile and personal communications, mmic technology is an important factor since it can provide a means of mass producing the user terminal rf subsystems. Millimetre-wave integrated circuits do not yet however offer the high packing density and functionality which is now possible for lower frequency applications where lumped elements are used. This problem is influenced most of all by the extreme modelling difficulties encountered at frequencies above 30 GHz. This paper reviews the current state-of-the-art for cad techniques used in mmic design. It describes some limitations of the standard Smarttm library approach and looks at the application of commercial electromagnetic simulators in the design of both microstrip and cpw circuits.     

Compact bandpass filter realised using coupled linear tapered line resonators

A new compact bandpass filter composed of two coupled linear tapered line resonators is proposed. The two resonators are arranged in different planes. The filter is very small and has a very sharp response below its passband. It is also shown that this filter has a low insertion loss of 0.6 dB in the centre frequency and 10.5% 3 dB bandwidth.     

FEN filter design using tantalum and silicon integrated circuits

An economical approach to integrated active RC filter design is described. Complex filter networks are broken down into a series of cascadable second-order filter sections consisting of tantalum thin-film RC networks and semiconductor integrated operational amplifiers. Two building blocks are available for any desired frequency within a decade and for any desired filter function (e.g., low-pass, high-pass, band-pass, band-reject, all-pass, etc.). One building block is for low Q realizations and contains one amplifier; the other is for high Q realizations and contains two. The considerable versatility of this approach is obtained by 1) a network synthesis approach based on decomposing a given second-order function into a low Q asymptotic approximation of this function in cascade with an active frequency emphasizing network and 2) by the characteristics of tantalum and silicon integrated circuits.     

Current mode allpass/notch and bandpass filter using single CCII

A current mode second-order allpass notch and bandpass filter using a single CCII, two grounded capacitors and four resistors is proposed. The allpass and notch output current signals, taken out through port z of a CCII and having high output impedance, can be obtained by tuning a resistor in the proposed network. The resonance angular frequency and quality factor of the new network have the advantages of low passive sensitivities and are insensitive to the current tracking error of the nonideal CCII.<>     

Low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer tuning

A low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer (PET) tuning is presented. At the 3.5 GHz passband, the insertion loss is 1.48 dB, and the transmission zeros at 3.05 and 4.08 GHz have a rejection of 55 dB. The rejection at the 7 GHz second harmonic is 50 dB. A PET tunes the bandstop sections to obtain a tunable suppression (>45 dB) around the second harmonic from 5.35 to 7.8 GHz.     

Differential-mode ultra-wideband bandpass filter on microstrip line

A differential-mode ultra-wideband (UWB) bandpass filter on a microstrip line is proposed and implemented with good common-mode suppression. A sixth-stage branch-line differential-mode bandpass filter is designed with the specified UWB passband. By introducing two pairs of open-circuited stubs in the symmetrical plane, the differential-mode frequency response remains unchanged but its common-mode counterpart is reshaped to achieve the stopband in the overall UWB. A filter is then fabricated for experimental verification of the proposed technique.     

Ultra-wideband bandpass filter on aperture-backed microstrip line

A novel ultra-wideband (UWB) bandpass filter is proposed on an aperture-backed microstrip line. With an aperture on the ground, a non-uniform resonator is constructed with the first three resonant modes occurring within the UWB band while the parallel coupling between resonator and feeders is largely enhanced. The designed filter exhibits good UWB passband behaviour with insertion loss <1.0 dB and group delay variation <0.25 ns.     

A V-band planar narrow bandpass filter using a new type integrated waveguide transition

A surface mountable planar narrow bandpass filter is proposed and demonstrated at V-band. The filter is constructed using an integrated waveguide in an alumina substrate employing a novel microstrip line to waveguide transition. The insertion loss per one transition is less than 0.1 dB over 43 to 73 GHz. A fabricated three-pole Chebyshev filter exhibits an insertion loss of 3 dB with a 3.3% bandwidth at a center frequency of 62 GHz and the return loss is better than 15 dB in the passband.     

Waveguide/resonant-disc circuits for millimetre-wave devices

Bias circuits using resonant discs have been employed for millimetre-wave transferred-electron (TE) diodes operating at their second or third harmonic frequencies in the V (50?75 GHz) and W (75?110 GHz) bands. It is shown that this type of circuit exhibits resonances at frequencies in the lower millimetre-wave range, corresponding to the fundamental oscillation frequency of diodes typically used. In addition, the circuit provides efficient coupling to the waveguide circuit at the higher (harmonic) operating frequency. By tuning the fundamental oscillation frequency of a number of resonant discs, the power-frequency spectrum of the TE device can be determined, which is demonstrated for a device with its maximum third-harmonic power output at 94 GHz.     

新型CRLH传输线带通滤波器设计

设计了一种新型双负介质传输线结构,该传输线结构具有负的磁导率和负的介电常数,同传统的混合左右手(composite right/left-handed,CRLH)传输线相比,该结构以更简单的构成、更小的尺寸实现了更好的左手媒质特性。应用该结构设计制作了一个任意可调双频带谐波抑制带通滤波器,测量结果显示:该滤波器第一个通带位于2.45 GHz,具有0.5 dB的插损和56%(1 400 MHz)的3 dB带宽;第二个通带位于5.8 GHz,具有1 dB的插损和27%(1 600 MHz)的3 dB带宽。这种CRLH传输线滤波器在无线通信、导航等多频带微波系统中具有良好的应用价值。     

Dual-mode triangular-patch bandpass filter using spur-lines

Without any perturbations on the surface of the patch resonator or orthogonal feed lines, a new microstrip dual-mode triangular-patch bandpass filter with low insertion loss and one transmission zero is presented. The degenerate modes are realised by use of the input/output spur-lines. It has been verified by simulation and measurement.     

基于环形谐振器的平衡式带通滤波器

提出了一种基于多模环形谐振器实现的平衡式带通滤波器, 其主要由加载了电阻和短路枝节的环形谐振器和两对平衡端口构成.所提出的滤波器能够以单个谐振器获得差模的双模响应, 并且具有结构简单, 共模抑制高, 带宽可进行有限控制(4% ~ 9%)的优点.为验证理论预期的可实现性, 在RO4003C基板上设计了一个工作在1.87 GHz的平衡式带通滤波器.实验结果表明该滤波器的20-dB阻抗匹配带宽为8.9%, 中心频率处的插入损耗为0.86 dB, 在1 ~ 3 GHz频率范围内的共模抑制大于30 dB.