scispace - formally typeset
Search or ask a question

Showing papers in "IEEE Microwave and Wireless Components Letters in 2015"


Journal ArticleDOI
TL;DR: In this article, a dual-band rectifier with extended power range (EPR) and an optimal incident RF power strategy was proposed to achieve high power conversion efficiency (PCE) in an ultra-wide input power range by adopting a pHEMT in the proposed topology.
Abstract: This letter presents a novel dual-band rectifier with extended power range (EPR) and an optimal incident RF power strategy in the settings where the available RF energy fluctuates considerably. It maintains high power conversion efficiency (PCE) in an ultra-wide input power range by adopting a pHEMT in the proposed topology. Simultaneous RF power incident mode is proposed and preferred to the traditional independent mode for multi-band harvesting. Measured results show that more than 30% PCE is obtained with input power ranging from $-15~{\rm dBm}$ to 20 dBm and peak PCE of 60% is maintained from 5 to 15 dBm. Positive power gain is achieved from $-20~{\rm dBm}$ to more than 10 dBm. Investigation about the effect of RF power incident ratio on dual-band harvesting's performance is presented and it provides a good reference for future multi-band harvesting system design.

130 citations


Journal ArticleDOI
TL;DR: In this paper, a 5-band waveguide bandpass filter based on spherical resonators has been designed, and fabricated by 3-D printing, and a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection.
Abstract: A fifth order X-band waveguide bandpass filter, based on spherical resonators, has been designed, and fabricated by 3-D printing. In comparison with rectangular waveguide, spherical resonators have a higher unloaded quality factor, but at the same time suffer from closer higher order modes. In this letter, a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection. Stereolithography based 3-D printing is used to build the filter structure from polymer and a 25 $\mu{\rm m}$ thick copper layer is deposited to the filter. The measurement result of the filter has an excellent agreement with the simulations. The filter is also considerably lighter than a similar metal filter.

109 citations


Journal ArticleDOI
TL;DR: In this paper, a back-to-back E-shaped defected ground structure (DGS) and two-side loading scheme for miniaturized dual-band substrate integrated waveguide (SIW) bandpass filter (BPF) designs is presented.
Abstract: This letter reports a novel back-to-back E-shaped defected ground structure (DGS) and two-side loading scheme for miniaturized dual-band substrate integrated waveguide (SIW) bandpass filter (BPF) designs. The SIW loaded by novel DGS supports evanescent-mode wave propagation below the cut-off frequency of SIW, while achieves two transmission poles at the passband and two controllable transmission zero points. Furthermore, the novel loading scheme by loading different-sized DGS resonators on two sides of SIW is proposed for dual-band BPF designs. To validate the design and analysis, a 2.4/5.2 GHz filter prototype was designed. In good agreement with theoretical results, the measured results of the dual-band filter achieve insertion losses of 3.6 and 3.1 dB, and fractional bandwidths of 5.8% and 6.45% at 2.4 and 5.2 GHz, respectively. The filter size is only 408 mil $\times$ 420 mil.

108 citations


Journal ArticleDOI
TL;DR: In this article, a wideband fifth-order bandpass filter (BPF) is proposed and designed using the U-slotted substrate integrated waveguide (SIW) cavities.
Abstract: A wideband fifth-order bandpass filter (BPF) is proposed and designed using the U-slotted substrate integrated waveguide (SIW) cavities. The U-shape slots, etched on the SIW cavity, are used to form up a new multiple-mode resonator (MMR) in order to achieve a wide passband of operation while keeping the overall size of the filter circuit to be much compact. The proposed fifth-order SIW filter is 2.5 times in size reduction compared with the traditional fifth-order SIW filters using the single-mode SIW cavities. In order to prove the validity, one wideband SIW BPF on a single layer printed circuit board (PCB) is designed and experimentally examined. The measured results show that the filter achieves an insertion loss of 1.1 dB at 8.5 GHz, return loss of higher than 11 dB and 3 dB fractional bandwidth of 42%. The measured results are in good agreement with the simulated results.

106 citations


Journal ArticleDOI
TL;DR: A phase-based algorithm based on a logarithmic method, applicable to UWB radars and suitable to real-time monitoring, is proposed to detect the phase variations of reflected pulses caused by the tiny cardiac motions.
Abstract: In this letter, a phase-based algorithm based on a logarithmic method, applicable to UWB radars and suitable to real-time monitoring, is proposed to detect the phase variations of reflected pulses caused by the tiny cardiac motions Compared with conventional FFT vital signs detection method, this algorithm demonstrates advantage in respiration harmonics suppression and avoidance of intermodulation between respiration and heartbeat signals Furthermore, it is experimentally shown that UWB Doppler radar is capable of multiple heartbeats detection and subject identification/localization

103 citations


Journal ArticleDOI
TL;DR: In this article, a stub loaded resonator (SLR) is proposed to achieve dual-band or tri-band differential-mode bandpass response with a high common-mode suppression.
Abstract: A stub loaded resonator (SLR) is presented in this letter, which can achieve dual-band or tri-band differential-mode (DM) bandpass response with a high common-mode (CM) suppression. By changing the length of the center-loaded stub, the resonant frequency of the CM can be varied without affecting that of the DM. This helps in simplifying the design and tuning processes of the balanced filters. In order to validate its practicalbility, two balanced bandpass filters (BPFs) with two and three DM passbands and good CM suppression are designed. Good agreement between simulated and measured results is observed. To our best knowledge, the proposed balanced tri-band BPF is the first ever reported.

93 citations


Journal ArticleDOI
TL;DR: The proposed technique overcomes several limitations of state-of-the-art methods, the scalability is hugely improved and tens of random parameters can be simultaneously treated within the polynomial chaos framework.
Abstract: This letter proposes a general and effective decoupled technique for the stochastic simulation of nonlinear circuits via polynomial chaos. According to the standard framework, stochastic circuit waveforms are still expressed as expansions of orthonormal polynomials. However, by using a point-matching approach instead of the traditional stochastic Galerkin method, a transformation is introduced that renders the polynomial chaos coefficients decoupled and therefore obtainable via repeated non-intrusive simulations and an inverse linear transformation. As discussed throughout the letter, the proposed technique overcomes several limitations of state-of-the-art methods. In particular, the scalability is hugely improved and tens of random parameters can be simultaneously treated within the polynomial chaos framework. Validating application examples are provided that concern the statistical analysis of microwave amplifiers with up to 25 random parameters.

87 citations


Journal ArticleDOI
Yiming Zhang1, Ting Lu1, Zhengming Zhao1, Kainan Chen1, Fanbo He1, Liqiang Yuan1 
TL;DR: In this article, the authors used the intermediate-coil structure to transfer the same power to multiple loads over various distances, which indicates that the intermediate coils work both as relay resonators and as power receivers.
Abstract: Resonant wireless power transfer has attracted much attention in recent decades. In some practical applications such as wireless sensor networks, multiple-load transfer over various distances is required. In this letter, the intermediate-coil structure is utilized to transfer the same power to multiple loads over various distances, which indicates that the intermediate coils work both as relay resonators and as power receivers. The mathematical model is built and in-depth analysis is conducted. Four important factors, namely the source matching factor, the load matching factor, the transfer quality factor, and the reflected impedance factor, are employed to build the mathematical model of $n$ -load transfer. The conditions to transmit the same power to all the loads attached in each relay resonator are investigated. The optimal load resistance and the highest efficiency with the same load resistance are derived. The theoretical calculations and the experimental results of double-load and three-load transfer confirm the analysis.

82 citations


Journal ArticleDOI
TL;DR: In this article, a substrate integrated waveguide (SIW) resonator sensor was designed to measure the complex permittivity of liquids through a slot opened on the top plane.
Abstract: This letter presents a novel substrate integrated waveguide (SIW) resonator sensor that is specifically designed to measure the complex permittivity of liquids. The resonant characteristics of the sensor are influenced by liquids through a slot opened on the top plane. The inverse problem of obtaining permittivity is solved with artificial neural network. Experiments were performed with an SIW resonator sensor designed at C band. Experimental data were reported and they agreed well to the reference values. The sensor is simple and low cost, which may be applied to permittivity measurements in applications at the industrial, scientific and medical (ISM) frequencies.

81 citations


Journal ArticleDOI
TL;DR: In this paper, a dual-band differential bandpass filter with controllable differential-mode (DM) center frequencies, and high common-mode suppression as well as band-to-band isolation is proposed.
Abstract: A dual-band differential bandpass filter with controllable differential-mode (DM) center frequencies, and high common-mode (CM) suppression as well as band-to-band isolation, is proposed in this letter. The presented filter is implemented based on the substrate integrated waveguide (SIW) technology. The first DM passband can be derived by the dominant modes, while the second DM passband response can be obtained by employing the higher order modes. The center frequencies of two DM passbands can be tuned by changing the dimension parameters. To improve the CM suppression, four slotlines with different locations are etched on the top metal plane. The measured and simulated results are in good agreement.

77 citations


Journal ArticleDOI
TL;DR: In this article, a new type of Frequency Selective Surface (FSS) with miniaturized resonator element is proposed, which produces a stable angular response up to 80 degrees for TE and TM incident angles.
Abstract: A new type of Frequency Selective Surface (FSS) with miniaturized resonator element is proposed. The FSS structure is shown to have a FSS unit cell dimension that is miniaturized to 0.067 $\lambda_{{{0}}}$ . Miniaturization of the FSS unit cell is achieved by coupling two meandered wire resonators separated by single thin substrate layer. The capacitance due to the small separation between the meandered wire elements results in a lowering of the resonant frequency. To demonstrate the validity of the design, the meandered wire resonator FSS was fabricated and tested using a free space measurement facility. The FSS produces a stable angular response up to 80 degrees for TE and TM incident angles.

Journal ArticleDOI
TL;DR: In this article, a planar microstrip resonator was used for real-time sensing of fluid properties at microwave frequencies with a quality factor of 22,000 at 1.4 GHz for water-based concentration detection.
Abstract: A novel electromagnetic sensor operating at microwave frequencies with quality factor of 22,000 at 1.4 GHz for real-time sensing of fluid properties is presented. The core of the sensor has a planar microstrip resonator, which is enhanced using an active feedback loop. The resonance frequency and quality factor of the sensor show clear differentiation between analytes composed of common solvents. To evaluate the sensor for water based concentration detection, we have demonstrated that KOH dilutions as low as 0.1 mM are detectable. The proposed sensor has advantages of inexpensiveness and high resolution as well as capability for miniaturization and CMOS compatibility.

Journal ArticleDOI
TL;DR: In this paper, the performance of 3-D printed transmission lines is compared to traditional-made versions of transmission lines at frequencies up to 10 GHz with respect to characteristic impedance, effective dielectric constant (EDC), and conductor loss.
Abstract: 3-D printing is enabling next generation manufacturing of RF and microwave circuits but little work has been done to demonstrate the true potential of this approach. This study shows that transmission lines fabricated using 3-D printing equipment are comparable in performance to traditionally-made versions. Basic transmission line parameters such as characteristic impedance, effective dielectric constant, dielectric loss, and conductor loss are modeled and measured for a variety of materials and types of transmission lines at frequencies up to 10 GHz. Data are given for use in future 3-D printed RF designs.

Journal ArticleDOI
TL;DR: In this paper, a microstrip diplexer consisting of two new types of ring filters is presented, which is able to move one of transmission zeros closer to its passband corner by connecting the feeding capacitors at different locations of the resonant ring.
Abstract: -A microstrip diplexer consisting of two new types of ring filters is presented in this letter The proposed ring filter is able to move one of transmission zeros closer to its passband corner by connecting the feeding capacitors at the different locations of the resonant ring Thus, a diplexer implemented by connecting two kinds of ring filters with different feeding features can achieve the required isolation for the small channel separation Then an open-stub is added at the common input port of the channel filters to achieve the required input matching at the two passbands of the diplexer A diplexer prototype with two passbands at 175 GHz and 185 GHz with a channel separation 40 MHz was fabricated The measured insertion losses in the pass bands are all less than 21 dB The isolation between the two channels is greater than 20 dB and the input return losses of the three ports are about 20 dB

Journal ArticleDOI
TL;DR: In this paper, a narrow-band balanced bandpass filter (BPF) using two coupled rectangular dielectric resonators (DRs) is proposed, which is tuned far away from the dominant mode in spectrum by optimizing the DR size so that the commonmode suppression in the differential passband can be improved significantly.
Abstract: For the first time, a novel narrow-band balanced bandpass filter (BPF) using two coupled rectangular dielectric resonators (DRs) is proposed. According to the electromagnetic (EM) field properties of the DR, the $TE_{11\delta}$ mode, as a dominate mode of the DR, can be differentially excited for constructing the fundamental passband of the balanced BPF. Meanwhile, the $TM_{11\delta}$ mode of the DR, functions as a common-mode response in this design, is tuned far away from $TE_{11\delta}$ in spectrum by optimizing the DR size so that the common-mode suppression in the differential passband can be improved significantly. To validate the proposed design concept, a second-order narrow-band balanced BPF is designed, fabricated and measured. The measured results show good agreement with the simulation data.

Journal ArticleDOI
TL;DR: In this paper, the design of substrate integrated waveguide (SIW) diplexers, based on combline triplet sections with transmission zeros (TZs) placed below and above the passband, is presented.
Abstract: The design of substrate integrated waveguide (SIW) diplexers, based on combline triplet sections with transmission zeros (TZs) placed below and above the passband, is presented. In order to control the location of the TZs, positive and negative couplings are conveniently provided. A highly compact implementation based on circular substrate integrated coaxial resonators is proposed. An X–band diplexer with channel center frequencies at 9.5 and 10.5 GHz and absolute bandwidths of 400 MHz is designed. The structure shows important advantages in terms of size reduction, while keeping good insertion losses as well as high rejection and isolation levels.

Journal ArticleDOI
TL;DR: In this paper, a two-pole tunable combline filter that allows for operational agility of the center frequency, passband bandwidth, and locations of upper and lower transmission zeros is proposed.
Abstract: In this letter, a two-pole tunable combline filter that allows for operational agility of the center frequency, passband bandwidth, and locations of upper and lower transmission zeros is proposed. To increase the tunable range of constant absolute-bandwidth for all frequency tuning states, a novel T-type bandwidth-control network was devised between resonators to flexibly tune the coupling coefficient without limitations imposed by the available varactor capacitance. By use of tunable source-load coupling, two tunable transmission zeros were produced on both sides of the passband to significantly improve filter selectivity and to dynamically afford interference suppression. A second-order 1.7–2.7 GHz filter with 1 dB constant bandwidth tuning from 50 to 110 MHz and transmission zero locations tuning from 300 to 700 MHz with respect to the passband was developed and fabricated. Good agreement was obtained between the simulated and experimental results.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a new filter based on substrate integrated folded waveguide (SIFW) technology, which exhibits compact size and good out-of-band rejection.
Abstract: This letter presents a new filter, based on substrate integrated folded waveguide (SIFW) technology, which exhibits compact size and good out-of-band rejection. The filter is based on a SIFW cavity, which guarantees size reduction, and the out-of-band rejection is controlled by the suppression and tuning of the high-order cavity modes. A detailed investigation of the cavity mode spectrum is presented, to illustrate the operation principle and the design of the filter. The interesting feature of this filter is the possibility to design the pass band and the return band by simply tuning the mode spectrum of the cavity, which is practically unaffected by the connection to the excitation ports. The fabrication and testing of a prototype operating at 4.5 GHz validate the proposed filter topology.

Journal ArticleDOI
TL;DR: In this paper, the angular independent dual-band FSS with closely spaced response is discussed, and the proposed single layer FSS comprises of unit cell resembling crooked cross geometry convoluted and branched to provide dual resonant paths.
Abstract: A novel angular independent dual-band FSS with closely spaced response is discussed in this letter. The proposed single layer FSS comprises of unit cell resembling crooked cross geometry convoluted and branched to provide dual resonant paths. The FSS functioning as a band stop filter at 2.54 and 3.54 GHz works as a shielding component for S band operation. The unit cell size of the proposed FSS is $0.088 \lambda \times 0.088 \lambda$ where $\lambda$ corresponds to the wavelength of the first resonant frequency. Both the bands are closely spaced providing the frequency ratio of upper to the lower resonant frequency value of 1.39. Additionally, the proposed dual-band FSS is symmetrical in nature, thereby providing identical stop-band response for both TE and TM operation modes. It also exhibits highly stable angular stability. Prototype of the proposed FSS is fabricated and its simulated results are compared with the experimental results.

Journal ArticleDOI
TL;DR: In this paper, a modified simplified real frequency technique (SRFT) was employed to optimize fundamental impedance and control the harmonic impedance directly with transmission lines (TLs) to overcome the limitation of the qualification in transforming lumped components of filter prototype to transmission lines.
Abstract: This letter presents a highly efficient broadband continuous Class- ${\rm F} ^{-1}$ power amplifier (PA), which employs the modified simplified real frequency technique (SRFT). In highly efficient PA design, a low-pass matching method is preferred for its harmonic impedance controlling. However, the qualification ( $ ) in transforming lumped components of filter prototype to transmission lines (TLs) imposes a restriction on its application. To overcome this limitation, a modified SRFT procedure is employed to optimize fundamental impedance and control the harmonic impedance directly with TLs. The proposed design strategy is experimentally verified by a 1.7~2.8 GHz PA design with 80.4% maximum efficiency and 10-W output power. The 100 MHz long term evolution advanced (LTE-A) signal is applied to this PA and the linearization result shows a well $-46.4~{\rm dBc}$ performance by digital pre-distortion (DPD) at 2.55 GHz.

Journal ArticleDOI
TL;DR: In this article, the first 40 Gb/s monolithically integrated silicon photonics linear receiver (Rx) comprising a germanium photodiode (Ge-PD) and a linear transimpedance amplifier (TIA) was presented.
Abstract: This letter presents the first 40 Gb/s monolithically integrated silicon photonics linear receiver (Rx) comprising a germanium photodiode (Ge-PD) and a linear transimpedance amplifier (TIA). Measured optical-electrical (O/E) 3 dB bandwidth (BW) of the Rx is 31 GHz. At 40 Gb/s, the Rx achieves a sensitivity of $-3~{\rm dBm}$ average optical input power with BER of $2.5\times 10^{-11}$ . It operates at $\lambda =1.55 ~\mu{\rm m}$ wavelength, uses 3.3 and 3.7 V power supplies, dissipates 275 mW of power, provides maximum differential output amplitude of $500 ~{\rm mV}_{\rm pp}$ , and occupies an area of $3.2~{\rm mm}^{2}$ . The presented receiver achieves the highest bit rate among the published work in monolithically integrated silicon photonics receivers.

Journal ArticleDOI
TL;DR: In this article, a tri-band bandpass filter with a wide stopband using asymmetric stub-loaded resonators (ASLR) is presented, where the harmonic responses are suppressed effectively by forming an uncoupled section at the end of the ASLRs, and the stopband region is formed from 3.7 to 7 GHz.
Abstract: This letter presents a tri-band bandpass filter (BPF) with a wide stopband using asymmetric stub-loaded resonators (ASLR). A tri-band filter sample was fabricated by using two ASLRs with coupled I/O ports. By properly tuning the electrical length ratios of the ASLRs ( $\alpha$ and $\gamma$ ), three passbands can be designed at 1.4, 2.4, and 3.5 GHz. The harmonic responses are suppressed effectively by forming an uncoupled section at the end of the ASLRs, and the stopband region is formed from 3.7 to 7 GHz with a rejection level of 30 dB. The measured results of the fabricated tri-band BPF exhibit good agreement with simulated results.

Journal ArticleDOI
TL;DR: In this paper, two types of modified open-or short-circuited stub-loaded $\lambda/4$ resonators and their applications to second-order dual-band bandpass filters are presented.
Abstract: Two types of modified open- or short-circuited stub-loaded $\lambda/4$ resonator and their applications to second- order dual-band bandpass filters are presented in this letter Based on the resonance characteristics analysis, it is found that the first two resonant frequencies of the two resonators can be independently controlled Furthermore, different frequency ratios can be achieved by loading different stubs Finally, to illustrate the proposed idea, two second-order dual-band filters with controllable bandwidths are designed, fabricated and measured The measured results are in good agreement with the full-wave simulation results

Journal ArticleDOI
TL;DR: In this article, a high selectivity bandpass filter with open stubs using dual-mode ring resonator is presented, which can be adjusted conveniently by only changing the characteristic impedances of the coupled lines.
Abstract: A high selectivity bandpass filter loaded with open stubs using dual-mode ring resonator is presented in this letter. Sixth-order passband with six transmission zeros close to the passband is realized with two open stubs and open/shorted coupled lines. The transmission zeros near the passband can be adjusted conveniently by only changing the characteristic impedances of the coupled lines. For demonstration, a planar bandpass filter (3 dB bandwidth 20.6%) is designed and fabricated. Good filtering performance and high selectivity for the filter are realized and experimentally verified.

Journal ArticleDOI
TL;DR: Based on a symmetrical structure of a simple uniform line loaded by a stepped-impedance open stub (SIS) connected at its center, the proposed design method employs simultaneously the optimization of a defined objective function in the range of frequency 3.1-10.6 GHz and the transmission zeros at cut-off frequencies for a rapid convergence as discussed by the authors.
Abstract: In this letter, a new design method of ultra wideband bandpass filter (UWB BPF) is proposed. Based on a symmetrical structure of a simple uniform line loaded by a stepped-impedance open stub (SIS) connected at its center, the proposed design method employs simultaneously the optimization of a defined objective function in the range of frequency 3.1–10.6 GHz and the transmission zeros at cut-off frequencies for a rapid convergence. Obtaining different filter sizes with good performance, the compact UWB BPF is simulated, fabricated, and measured. A good agreement between simulation and measurement is obtained while achieving good performances such as a return loss better than 10 dB, an upper stopband attenuation higher than 20 dB up to 17.6 GHz, and a sharp selectivity.

Journal ArticleDOI
TL;DR: In this article, the InP HEMT amplifier achieves a noise figure as low as 11.1 dB with an associated gain of 13.6 dB at 0.85 THz.
Abstract: In this letter, the first packaged THz solid-state amplifier operating at 0.85 THz is reported. The InP HEMT amplifier achieves a noise figure as low as 11.1 dB with an associated gain of 13.6 dB at 0.85 THz using high ${\bf f}_{\bf MAX}$ InP HEMT transistors in a 10-stage coplanar waveguide integrated circuit. Output power up to 0.93 mW is measured.

Journal ArticleDOI
TL;DR: In this paper, a dual-band impedance transformer which can match two unequal arbitrary complex loads at two frequencies was proposed and the required nonlinear simultaneous equations were derived to obtain the physical parameters of transmission lines and stubs.
Abstract: This letter presents a $\pi$ -model dual-band impedance transformer which can match two unequal arbitrary complex loads at two frequencies. The required nonlinear simultaneous equations are derived to obtain the physical parameters of transmission lines and stubs. Return loss for the proposed matching circuit is measured to validate the results of the presented structure simulations. Excellent agreement between analytical and measured results confirms the proposed structure.

Journal ArticleDOI
TL;DR: In this article, a balanced-to-balanced power divider (PD) is proposed by etching both slot and aperture on the common ground of the back-toback microstrip balanced PD, which can achieve wide and high commonmode suppression while keeping the PD function for differential-mode signals.
Abstract: In this letter, a balanced-to-balanced power divider (PD) is proposed By etching both slot and aperture on the common ground of the back-to-back microstrip Wilkinson PD, the proposed balanced-to-balanced PD can achieve wide and high common-mode (CM) suppression while keeping the PD function for differential-mode signals Compared with previous technologies of CM suppression for back-to-back microstrip balanced circuits, the proposed one has the advantage of compact size Furthermore, the proposed PD shows enhanced bandwidth for matching and isolation A prototype is realized with the size of $035 \lambda_{\rm g} \times 04 \lambda_{\rm g}$ The measured results show relative frequency bandwidth for $\vert S_{dd11}\vert dB of 85% The fractional bandwidths for $\vert S_{dd32}\vert, \vert S_{cc21}\vert$ and $\vert S_{cc32}\vert$ under ${-}20$ dB are 44%, 44% and 55%, respectively

Journal ArticleDOI
TL;DR: In this article, the authors report on the design, fabrication and characterization of a high-power and broadband 105-120 GHz Schottky diode frequency tripler based on a novel on-chip power combining concept that allows superior power handling than traditional approaches.
Abstract: We report on the design, fabrication and characterization of a high-power and broadband 105–120 GHz Schottky diode frequency tripler based on a novel on-chip power combining concept that allows superior power handling than traditional approaches. The chip features twelve anodes on a 50 $\mu{\rm m}$ thick GaAs substrate. At room temperature, the tripler exhibits a 17% 3 dB bandwidth and a $\sim 30\%$ peak conversion efficiency for a nominal input power of around 350–400 mW, and $\sim 20\%$ efficiency for its maximum operational input power of 800–900 mW. This tripler can deliver maximum power levels very close to 200 mW. The on-chip power-combined frequency tripler is compared with a traditional tripler designed for the same band using the same design parameters.

Journal ArticleDOI
TL;DR: In this article, a conformal spiral type Implantable antenna at Medical Implanted Communication Service (MICS) band was proposed to overcome the telemetry and wireless powering problems associated with the recently invented leadless pacemaker.
Abstract: In this letter, we address the telemetry and wireless powering problems associated with the recently invented leadless pacemaker. To overcome the telemetry problem, we propose a conformal spiral type Implantable antenna at Medical Implanted Communication Service (MICS) band. In addition, we also apply the recently proposed midfield wireless power transfer (WPT) technique at 1.5 GHz to avoid the bulky energy storage component. We simulate and experimentally measure the performance of the implantable antenna by using porcine heart tissue. Our research shows that, the implantable antenna and wireless power transfer scheme can be implemented in a leadless pacemaker without any significant coupling between them.