Novel folded SRR-loaded waveguide bandpass filters

A novel class of E-Plane, low-cost, compact and metamaterial-based filter structure using FSRRs for microwave, millimeter wave applications has been proposed. The proposed FSRR-loaded waveguide bandpass filter has been designed and simulated at 9.45 GHz. The structure can be easily realized with a single metal insert within a rectangular waveguide. This kind of filter can be found in applications particularly in the mm-wave range circuits, e.g. in diplexers and multiplexers

Novel SRR loaded waveguide bandstop filters

Two types of novel split ring resonator (SRR) loaded rectangular waveguide bandstop filter structures have been presented. The first proposed SRR-loaded waveguide bandstop filter has been designed simulated and tested. Using the combination of the split ring resonators, conductive wireline and transversely placed metal septa, the composite material has been built and inserted into the hollow rectangular waveguide to form an SRR-loaded waveguide unit. The bandstop filter has been constructed by cascade of the two resonator unit cells. The second proposed multilayer SRR loaded waveguide bandstop filter has been designed and simulated. Three transverse periodic SRRs are present on either side of the dielectric blocks

A multicarrier amplifier design linearized trough second harmonics and second-order IM feedback

A novel linearisation technique for reduction in the first and second kind of the third-order intermodulation products was applied in this paper. The second harmonics and second-order intermodulation products are led from the output to the input of a power amplifier through a feedback loop. The power amplifier including the feedback loop components (bandpass filter, phase shifter and attenuator) was designed as a hybrid microwave integrated circuit by using program ADS. The phase and amplitude of the loop signals are the adjustable parameters. Therefore, a voltage that controls a phase shift of the phase shifter and a control current of a PIN diode in the attenuator circuit were optimised to obtain a reduction in the third-order intermodulation distortion. For three fundamental signals at the power amplifier input, the lowest improvement of 13 dB for the first and 18 dB for the second kind of the third order intermodulation product levels was achieved

Design of generalized Chebyshev lumped element filters by computer optimisation

A numerical method for the optimization of symmetrical lumped element low-pass and band-pass filters with a generalized Chebyshev response is considered. By exploiting the fact that a network based on generalized Chebyshev prototype has a prescribed number of turning points in the insertion loss and an identical number of independent parameters which can be assigned as variables to adjust their levels, the method gives fast convergence

Inkjet Printed Bandpass Filters and Filtennas using Silver Nanoparticle Ink on Flexible Substrate

This paper presents an inkjet printed CPW filtenna designed at 5.8 GHz. The proposed structure consists of a CPW pseudo-interdigital bandpass filter and a CPW inset-fed antenna. The bandpass filter is fabricated using inkjet printing technology. The structure is printed on flexible Kapton substrate with polyimide film using silver nanoparticle ink. The filter is then used to suppress the spurious harmonics of the antenna. Measurements from the fabrication confirm the accuracy of the design method and the simulation results

Linearization of multichannel amplifiers with the injection of second harmonics into the amplifier and predistortion circuit

A linearization technique that uses the injection of the fundamental signal second harmonics together with the fundamental signals at the amplifier input has been extended in this paper by introducing the injection the second harmonics into nonlinear microwave amplifier and so-called predistortion circuit. Predistortion circuit produces the third-order intermodulation signals that are injected at the amplifier input together with the second harmonics making the linearization procedure more independent on the phase variation of the second harmonics. In addition, a considerably better improvement is attained for the power of fundamental signals close to 1-dB compression point by applying the linearization technique proposed in this paper in comparison to the linearization with the injection of the second harmonics merely in the nonlinear amplifier

Piezoelectric anisotropy: Enhanced piezoelectric response along nonpolar directions in perovskite crystals

This paper discusses the mechanisms that can contribute to the enhanced longitudinal piezoelectric effect along nonpolar directions in perovskite crystals, such as BaTiO3, PbTiO3, KNbO3, Pb(Mg1/3Nb2/3)O3-PbTiO3 and Pb(Zn1/2Nb2/3)O3-PbTiO3. Piezoelectric anisotropy is discussed in relation to temperature induced phase transitions, compositional variation in solid solutions with morphotropic phase boundaries, applied electric fields, the domain wall structure and domain wall displacemen

Hybrid Manufactured Waveguide Resonators and Filters for mm-Wave Applications

Additive and hybrid manufactured waveguide resonators and bandpass filters for mm-wave applications are presented. A Ka band 3D printed waveguide resonator with inductive windows and 28 GHz 5G band hybrid manufactured waveguide resonator and bandpass filter are designed. Hybrid manufacturing combines 3D polymer printing and conventional metal processing technologies. In order to illustrate the accuracy of the design, a 3D printed waveguide transmission line and resonator with the resonant frequency of 33 GHz are fabricated and tested

Ultra Compact Inline E-Plane Waveguide Bandpass Filters Using Cross Coupling

This paper presents novel ultra-compact waveguide bandpass filters that exhibit pseudo elliptic responses with ability to place transmission zeros on both sides of the passband to form sharp roll offs. The filters contain E plane extracted pole sections cascaded with cross-coupled filtering blocks. Compactness is achieved by the use of evanescent mode sections and closer arranged resonators modified to shrink in size. The filters containing non-resonating nodes are designed by means of the generalized coupling coefficients (GCC) extraction procedure for the cross-coupled filtering blocks and extracted pole sections. We illustrate the performance of the proposed structures through the design examples of a third and a fourth order filters with center frequencies of 9.2 GHz and 10 GHz respectively. The sizes of the proposed structures suitable for fabricating using the low cost E plane waveguide technology are 38% smaller than ones of the E plane extracted pole filter of the same order

Dissipative neutrino oscillations in randomly fluctuating matter

The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: it takes into account matter-induced, decoherence phenomena that go beyond the standard MSW effect. A widely adopted density fluctuation pattern is found to be physically untenable: a more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.Comment: 14 pages, plain-Te