A novel method for label-free detection of Escherichia coli relying on microwave sensing is proposed. transmission-type differential resonator array biosensor covered with polyclonal anti-Escherichia antibodies introduced providing a robust response high sensitivity detecting bacteria presence due to resonant operation combined. The selectivity given by the specific bacteria-binding antibodies. Low-Temperature Co-Fired Ceramics technology proposed be used implementation take advantage its...

An ultra-broadband multisection directional coupler designed in Monolithic Microwave Integrated Circuit (MMIC) technology has been presented. It shown for the first time that it is possible to achieve bandwidths exceeding one frequency decade, simultaneously taking under account technological constrains. The proposed composed of three coupled-line sections having different values electrical lengths and coupling coefficients. strongest coupled section as an asymmetric three-strip section,...

A microwave sensor realized in monolithic technology, intended for permittivity estimation with the use of a highly sensitive coupled-line section, is presented this paper. It also contains dedicated measurement circuitry as five-port correlator, therefore, simple scalar power can be utilized to obtain vector signal corresponding measured material without usage an external network analyzer. To suppress systematic errors arising from manufactured circuit's imperfections it equipped integrated...

A new approach to the synthesis of broadband branch-line couplers with arbitrary coupling level was investigated in this paper. It shown that operational bandwidth a classic coupler can be increased by utilizing N-section impedance transformers added each coupler’s ports. Furthermore, obtained response approximated Chebyshev polynomial. Moreover, it proven for such range coefficient values modification topology. The analysis electrical parameters proposed comprehensively investigated. To...

An investigation on the design of Lange couplers in suspended microstrip technique is presented. The chosen realization allows for minimization total losses coupler. theoretical analysis shows that can be compensated with proper selection dielectric stratification substrate, and by proposed compensation both isolation impedance match coupler enhanced. presented has been supported measurements a 3-dB directional exhibiting good electrical properties low losses.

The problem of the realization broadband quadrature directional couplers in UMS (United Monolithic Semiconductors) PH25 is thoroughly investigated. limitations selected technology are discussed with respect to couplers’ design. It shown that, such technologies, two major problems have be overcome achieve high-performance resulting integrated couplers, i.e., appropriate coupling together characteristic impedances, and equalization inductive capacitive coefficients that inherently different...

A novel concept of impedance transforming directional couplers for applications in balanced networks has been proposed. The proposed consist a tandem connection two asymmetric having different coupling coefficients. Theoretical analysis the shown and maximum achievable transformation ratio versus required reflection coefficient given tabular form. verified by measurements an coupler operating at center frequency 1 GHz, which equal R = 5 assumed.

In this paper, for the first time design of a tandem directional coupler operating in differential mode has been shown. To equalize phase velocities, proposed realized homogeneous multilayer structure. verify applicability such concept 3-dB differentially-fed coupler, at 1 GHz center frequency designed, fabricated, and measured.

In the paper design of coupled-line directional couplers is presented in which lines are not directly coupled. Instead an additional conductor utilized to provide coupling between two transmission lines. The proposed realization technique easily applicable practical designs and procedure does require advanced analysis multi-conductor coupled lines, instead a simple calculator for single microstrip line required.

In this paper a novel design of broadband reduced-length directional couplers for planar and MMIC applications has been presented. The proposed component utilizes two indirectly coupled-lines sections realizing the same coupling coefficient connected with uncoupled transmission-lines. To verify correctness method, 3-dB coupler 1 GHz center frequency designed, fabricated, measured. Moreover, monolithic version considered solution designed fabrication in OMMIC D01PH GaAs technology, operating...

The relation between load impedances and the characteristic impedance of rat-race ring has been derived. To minimize circuit size, 270°-long section replaced by a shorted coupled-line section. Moreover, to achieve appropriate coupling coefficient in required section, modified Lange structure consisting five-coupled lines applied. Furthermore, second proposed having improved operational bandwidth, which matching sections are added. theoretical analysis verified measurements fabricated...

A broadband rat-race coupler has been designed in a suspended stripline technique. For operation the needed phase inverter realized as shorted-coupled-line section. Additionally single section matching transformers have added to improve return losses. The technique chosen for minimizing coupler's described circuit experimentally verified, manufactured and measured. measurement results show good agreement with both electromagnetic analyses which prove correctness usefulness of presented...

In this paper, a design of miniaturized branch-line directional coupler is presented. The designed with balanced coupled-line sections, which are electrically shortened by the application lumped capacitors. To measure parameters coupler, appropriate baluns have been designed. has in GaAs PH25 UMS (united monolithic semiconductor) technology center frequency 24 GHz. measured power split equals 3 dB transmission/coupling imbalance not exceeding 0.6 dB. return losses equal 17 at frequency,...

The concept of reduced-length directional couplers composed two sections coupled-lines having appropriate electrical lengths between which uncoupled transmission-line are inserted, has been verified for differential excitation. It is shown, that broadband frequency characteristics, similar to the ones achieved classic three-section can be with use presented together shorter length overall circuit comparing solutions. A differentially-fed coupler operating at center 1 GHz designed and measured.

A novel concept of impedance-transforming transdirectional coupled-line directional couplers that feature maximum available impedance transformation ratio is proposed. It shown such can be designed as an appropriate connection two uncoupled two-wire transmission lines, having electrical lengths equal 90° and 270°. The conditions for ideal match isolation in are derived formulas describing the required characteristic impedances lines given. circuits input isolated port terminated with...

Design of coupled line 3dB directional couplers realized in suspended microstrip technique has been presented. The main goal was to minimize the insertion losses coupler, what achieved by a proper choice realization technique. As chosen geometry is asymmetric achieve good electrical performance resulting capacitive compensation utilized equalize and inductive coupling coefficients. Furthermore, distributed-element approach investigated for capacitances, due their physical size from...

A broadband, impedance transforming rat-race coupler designed in a suspended microstrip technique has been presented. The proposed structure allows to transform input impedances on coupled ports with ratio 2:1. Furthermore, improve operational bandwidth, additional, modified coupled-line sections have added at ports. chosen minimize the coupler's losses. described circuit theoretically analyzed, fabricated and measured.

The investigation results on the design of branch-line coupler have been presented. is designed as a differential circuit with use two-conductor substrate-integrated transmission-line technique. four-branch topology has employed in order to enhance operational bandwidth, whereas impedances transmission lines optimized allow for their physical realization.

In this paper, a bi-level microstrip differential directional coupler has been investigated. It shown that the equalization of coupling coefficients can be successfully made with use appropriate dielectric stack-up and conductor geometry. The application additional top layer ensure proper by lowering value capacitive coefficient to inductive one. theoretically investigated coupled-line section used for design 3-dB coupler. measurement results are compared theoretical ones.

A novel concept of a differential feeding network for four-node antenna/antenna arrays is proposed. The constructed out four-strip coupled-line directional coupler operating in mixed differential-nodal mode enabling direct interfacing front-ends with single-ended antennas. It shown, that such configuration provides at the outputs proposed four signals, which are equal amplitude and phase progression 90°. Thus, can be utilized generating either dual-circular polarization from 2× 2 antenna...

A new concept of broadband equal-split coupled-line directional couplers is proposed. The proposed are based on sections, all having the same coupling coefficient, and feature frequency characteristics similar to ones obtained for classic symmetrical three-section couplers. It shown that appropriate cascade- tandem-connected coefficients different electrical lengths allow achieving equal power split in a range together with quadrature differential phase response. Therefore, very flexible...

Abstract In this article, we present for the first time possibility of modal phase velocity compensation in differentially fed directional couplers designed inhomogeneous dielectric media. It is shown that an appropriate, structure, equalization even‐ and odd‐mode velocities propagating such can be made. The presented method has been verified experimentally by design measurements a fabricated coupler to show correctness applicability proposed solution. A 8‐dB as edgewise structure operating...

In this paper, a tandem connection of hybrid couplers realized in microstrip technique is presented. The proposed structure designed as two coupled-line sections having different electrical lengths and the same value coupling coefficient. Such approach can be used to reduce overall size component, what more attractive comparison classic topology. Furthermore, verify possibility implementation conjunction with active devices, directional coupler implemented balanced amplifiers utilized PCB...