In this letter, enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) were demonstrated based on lateral scaling of the 2-D gas channel using nanochannel array (NCA) structure. The NCA structure consists multiple parallel channels with nanoscale width defined by electron-beam lithography and dry etching. Because improved gate control from sidewalls partially relaxed piezoelectric polarization, fabricated 2 <formula formulatype="inline"...

A novel polarization-reconfigurable planar antenna is presented. The consists of an electronically reconfigurable polarizer integrated with a printed slot. By changing the states p-i-n diodes on polarizer, linearly polarized (LP) waves radiated by slot can be converted into either right-hand circularly (RHCP) or left-hand CP (LHCP) waves. contains 16 unit cells arranged as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math...

Although gold nanorods capped with hexadecyltrimethylammonium bromide (CTAB) have been prepared through the seed-mediated method for their use in diagnostics and therapeutics, toxicity of AuNRs@CTAB limits practical applications biomedical field. In this work, synthesis tuning at very low concentrations CTAB (as as 0.008 M) was successfully achieved by using method. Furthermore, we managed to optimize growth conditions changing amount seeds, AgNO3, and/or HCl. At concentrations, tunable size...

This letter presents the high-temperature performance of AlGaN/GaN HEMT direct-coupled FET logic (DCFL) integrated circuits. At 375 degC, enhancement-mode (E-mode) HEMTs which are used as drivers in DCFL circuits exhibit proper E-mode operation with a threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</sub> ) 0.24 V and peak current density 56 mA/mm. The monolithically E/D-mode deliver stable operations at degC: An E/D-HEMT...

A new class of in-phase and out-of-phase power dividers with constant equal-ripple frequency response wide operating bandwidth is presented in this paper. The proposed design based on microstrip-to-slotline transitions slotline resonators. slotted T-junction adopted to split the into two parts obtain wideband isolation between output signals at same time. characteristic impedance resonators determines in-band magnitude response. By reversing placement direction slotline-to-microstrip...

Abstract The Y 3 MgAl SiO 12 ceramics with pure phase were successfully synthesized by solid‐state sintering reaction method for the first time. Their microwave dielectric properties investigated as a function of temperature. microstructure characteristics and ionic occupation sites tetrahedral octahedral units characterized analyzed SEM &amp; energy dispersive spectrometer ( EDS ) Rietveld refinement X‐ray powder diffraction data. Crystal structure is isostructural to Al 5 O cubic garnet...

In this work, we study sensing-aided uplink transmission in an integrated sensing and communication (ISAC) vehicular network with the use of orthogonal time frequency space (OTFS) modulation. To exploit parameters for improving communications, must be first associated transmitters, which is a challenging task. We propose scheme that jointly conducts parameter association, channel estimation signal detection by formulating it as constrained bilinear recovery problem. Then develop message...

We report a low-density drain high-electron mobility transistor (LDD-HEMT) that exhibits enhanced breakdown voltage and reduced current collapse. The LDD region is created by introducing negatively charged fluorine ions in the between gate electrodes, effectively modifying surface field distribution on side of HEMT without using plate electrodes. Without changing device physical dimensions, can be improved 50% LDD-HEMT, collapse reduced. No degradation cutoff frequency (f <sub...

This letter introduces a broadband and compact output combiner for Doherty power amplifier (DPA). A grounded quarter Wavelength <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(\lambda/4)$</tex-math></inline-formula> line is added to the of peaking amplifier, which helps compensate bandwidth limiting effect that happens in conventional combiner. Frequency response analysis indicates stable impedance...

A tunable terahertz nanoantenna based on graphene is presented. The proposed antenna has a characteristic of dynamic frequency reconfiguration, high miniaturization, easy integration, low reflection coefficient, and good omnidirectional radiation pattern. attractive properties the potential to be used in nanoscale wireless communications sensing systems. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1792–1794,

This paper presents the design of a smart antenna that can achieve 3-D beam-scanning coverage. The consists novel planar feed array and cylindrical active frequency-selective surface (AFSS). First, an fed metallic reflector is studied as reference to validate characteristics in elevation plane. Then, AFSS assessed through simulation measurement results. Finally, complete structure containing collinear analyzed. A prototype at S-band has been designed, manufactured, measured. resulting shown...

This letter proposes a novel broadband, high-efficiency power amplifier (PA). The characteristics of Class-EF PAs and the large bandwidth advantages Class-J are effectively combined in proposed PA. By theoretically analyzing impedances traditional class-J PAs, we can consider possibility combining these two types PAs. conditions that need to be met derived. In order verify effectiveness method, wideband Class-EFJ PA is designed fabricated by using CGH40010F GaN HEMT. measurement results...

An extended version of the continuous-mode Class-GF power amplifier (PA) design theory is first proposed in this letter by analyzing impact input voltage waveform alterations caused nonlinearity on drain current waveform. Then, a novel impedance space explored under Thereafter, multioctave, high-efficiency continuous (ECCGF) PA component was implemented, fabricated, and measured with 10-W GaN HEMT device over 150% bandwidth from 0.4 to 2.8 GHz. The test result shows that 39–42-dBm output...

In this paper, the state-of-the-art integrated filtering antennas with dual-band operation are first reviewed. Then, two designs of microstrip a low-frequency ratio presented. The 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> design is dual-polarization (DBDP) antenna frequency 1.2 on single patch, by employing coupled resonator technique. Two bands at each polarization achieved vertically coupling hairpin patch through slot in...

A novel second-order antenna with filtering performance and two-octave harmonic suppression is proposed. In order to reduce the effects of harmonics antenna, two types antennas [planar inverted-F (PIFA) patch] different resonant characteristics are integrated into design. Compared traditional patch antennas, this work can not only eliminate high-order but also improve in-band bandwidth frequency selectivity. The second- fourth-order suppressed because detuned PIFA patch. third-order...

Abstract In this paper, a novel source second harmonic manipulation architecture achieving control at device input is proposed to solve the issue of reduced operating efficiency power amplifiers (PAs) caused by nonlinearity in continuous Class‐GF mode. The key lies use compact multibranch network match harmonics three design frequency points short‐circuit state, which can expand bandwidth while avoiding unexpected degradation. Considering necessity theoretical verification, broadband PA...

In perceptive mobile networks (PMNs), using 5G New Radio (NR) signals for direct sensing poses a significant challenge to practical implementation due the high computational complexity involved in estimating parameters. this paper, an efficient method is proposed incorporate both downlink active and passive estimate multiple parameters, including delays, angle of arrival (AoA), departure (AoD) Doppler. particular, it exploits synchronization signal blocks (SSBs) facilitate with remote radio...

A novel antenna with both frequency and pattern reconfigurability is presented. The achieved by integrating an active selective surface (AFSS) feed antenna. smart FSS comprises a printed slot array loaded varactors. dc biasing arrangement proposed to the slots vertically so that unwanted effects caused bias lines are minimized. monopole designed illuminate AFSS. resulting structure can operate in tuning range of 30%. By reconfiguring different sections cylinder into transparent or reflector...

This paper presents a novel hybrid design technique to minimize the number of layers transmitarray (TA) panel while maintaining 360° phase shift range. Two types unit cells, receive-transmit cell and frequency selective surface (FSS), are placed in same aperture. The resulting TA is very thin but does not sacrifice radiation efficiency array. an aperture-coupled square patch, FSS wide bandpass FSS. Both cells have three conductive printed on two substrates with total thickness 0.07λ0....

This paper proposes a method that employs novel hybrid continuous class-EFJ power amplifiers (PAs) as carrier PA to design broadband high-efficiency Doherty amplifier (DPA). Bandwidth characteristic of the proposed DPA is analyzed in detail. By proper selection related parameter values, up 78% fabrication bandwidth can be obtained. Post-harmonic tuning network applied improve and enhance efficiency. Then, closed process presented based on derived theories. For validation, operating 1.2-2.8...