Stub (electronics)

About: Stub (electronics) is a research topic. Over the lifetime, 8172 publications have been published within this topic receiving 75018 citations.

Analytical Design Methodology of Outphasing Amplification Systems Using a New Simplified Chireix Combiner Model

Abstract: An analytical design methodology of outphasing amplification systems is proposed using new simplified analytical expressions for the instantaneous efficiency and the input/output voltages of Chireix outphasing combiners. These expressions are derived first for ideal voltage sources with nonzero internal impedance and later for ideal Class-B amplifiers where dc current variation is incorporated. They take into account the impedance mismatch between the amplifiers and the lossless combining structure and account explicitly for the all of the combiner's electrical parameters. We show that the maximum achievable instantaneous combining efficiency can be controlled in position and in value through the judicious choice of the combiner's stub length and transmission-line characteristic impedance. We further show that, when this choice is combined with the amplified signal's distribution, the average combining efficiency can be precisely controlled and easily maximized. Various validations of the proposed expressions are performed by comparison with experimental and simulation results for various combiners as well as for a complete linear amplification with nonlinear components amplifier. Excellent agreement between simulations and measurements is obtained in all cases considered.

Differentially Fed Wideband Rectangular DRA With High Gain Using Short Horn

Abstract: A differentially fed rectangular dielectric resonator antenna (DRA) is presented. The DRA is excited by a microstrip gap between two identical transmission lines carrying a differential signal. It is shown that this new method can be adopted to excite the fundamental TE1δ1 mode in a rectangular DRA. Furthermore, by adding a stub to each transmission line, an additional nonradiating resonance is obtained that results in bandwidth enhancement. A conventional hybrid (rat-race) coupler is used for a single-end operation. A common ground plane is shared between the DRA (placed in + z -plane) and the hybrid coupler (placed in –z -plane) to preserve the footprint of the antenna. For | S 11| ≤ –10 dB, a wide impedance bandwidth of 30% is measured from 2.27 to 3.07 GHz. Additionally, a surface-mounted short horn (SMSH) is incorporated to enhance the boresight gain throughout the band. In measurements, an optimum boresight gain of 12.2 dBi with an improvement of 5.8 dB is obtained at 2.6 GHz using the proposed DRA with SMSH.

Design and development of novel miniaturized UHF RFID tags on ultra-low-cost paper-based substrates

Abstract: In this paper, an overview of design requirements and novel approaches for improved performance UHF radio frequency identification (RFID) tags is presented. Two matching techniques, inductively coupled structure and serial stub structure are discussed. Different antenna configurations are proposed, focusing on low-profile, low polarization mismatch and high directivity. Paper substrates, that could potentially utilize inkjet printing techniques, are also investigated for the realization of ultra-low-cost RFID tags.

Hybrid power combiner and amplitude controller

Abstract: A dipositif (10) consists of a hybrid power combiner and a controller comprises a hybrid network with multiple branches, provided with PIN diodes (35, 40) used for selective ground contact intermediate points (26 , 31) branch lines (26, 30). When the PIN diodes are biased in conditions of open circuit, the apparatus (10) behaves like a conventional hybrid combiner, intended for example to combine the power from two input sources (16, 21) at the outlet orifice (22) of the device. When the PIN diodes are biased in conduction conditions, thus allowing the ground contact of the intermediate points (26, 31) branch lines, the apparatus (10) behaves as a multiple stub filter adapted and tuned to the desired band. Substantially all the power supplied by a single source of input power (21) will in this case supply the output (22) of the device.

Compact ultra-wideband 90° phase shifter using short-circuited stub and weak coupled line

Abstract: A compact ultra-wideband 90° phase shifter based on a short-circuited stub and a weak coupled line (WCL) is proposed. The circuit configuration and derivation of S-parameters and phase difference are presented. The analysis result indicates that the phase deviation (PD) bandwidth can be extended to 200% by adjusting the coupling coefficient of the WCL. The fabricated phase shifter exhibits a bandwidth of 118% from 0.66 to 2.56 GHz for return loss >10 dB, insertion loss (IL) <0.5 dB and a PD of ±3.9°. Comparison shows that the proposed phase shifter not only has the most compact size with single-layer structures but also achieves the largest bandwidth and lowest IL. The design features low-cost, good design portability and convenient installation. Thus it is a good candidate for wideband and ultra-wideband applications.