In this paper, a 1-GS/s 12-bit pipelined folding analog-to-digital converter (ADC) fabricated in 40 nm CMOS technology is presented. A new encoding algorithm based on distributed quantization is proposed to simplify the quantization process of the structure with odd folding factor and reduce the hardware consumption of the circuit. The ADC achieves spurious free dynamic range (SFDR) > 72 dB and signal-to-noise and distortion ratio (SNDR) > 57 dB in low input frequencies.
This paper presents a design of CMOS source-degenerated active negative group delay (NGD) circuit by using bonding wire for a compact circuit size. The proposed circuit consists of two cascaded MOSFETs where parallel RLC resonator circuits are connected to the source of the MOSFETs. To reduce the size, the parallel RLC resonators are implemented with bonding wires and pads. For experimental verification, two-stage NGD circuits with slightly different center frequencies were designed. The measurement results show that the NGD bandwidth, group delay, and gain are 100 MHz, −2.5 ns, and 3 dB, respectively. The measured input/output return losses are higher than 8 dB and 14 dB, respectively, at the center frequency of 1.88 GHz.
This paper introduces a structure for Compensation of dynamic nonlinear mismatches in time-interleaved analog-to-digital converter (TIADC). The basic idea of the proposed compensation structure is to reconstruct error signal and then subtract the reconstructed error from the output signal of TIADC. The compensation performance can be improved progressively by cascading compensation structure. We also proposed the real-valued compensation structure, which is suitable for implementation in hardware.
In this paper, a novel 22.5° fan-shaped half-mode substrate integrated waveguide resonator (FSHMSIWR) is presented firstly. Based on it, a filter design method by suppression or utilization of higher-order modes is proposed. When feeding on magnetic wall, the fundamental mode (TM101) is excited to generate passband response, while the higher-order modes (TM201 and TM301) can be suppressed. A pair of complementary split-ring resonators (CSRRs) are introduced to strengthen the out-band rejection. Then a single-band bandpass filter (BPF) with ultra-wide and deep stopband is realized. When feeding on electric wall, the higher-order modes can be well excited, which provides flexibility to realize multi-band BPFs only by changing the feeding position. As verification, a single-band BPF and a tri-band BPF with source-load coupling are designed and fabricated. The measured results show good agreement with the simulated ones.
A novel compact multi-band frequency selective surface (FSS) with dual passbands and wide upper stopband is presented. The proposed FSS was originally a double-layer structure. The grid-double square loops (G-DSLs) are located at the bottom to achieve the dual passband characteristics. In order to realize wide upper stopband, a modified square ring and a Jerusalem cross (M-SR-JC) element structure at top and bottom are used. Considering the higher power engineering applications, the final FSS uses a multi-layer structure. The FSS provides two pass-bands centered at 3.8 and 5.8 GHz with relative bandwidths of 18.4% and 13.5%, respectively. It also provides wide stopband characteristics from 10.8 GHz to 14.5 GHz. The simulation and measurement are in good agreement. The novel FSS with dual passbands and wide upper stopband is compact; easy to design and fabricate, and achieves relatively stable multi-band response under different polarization states and different incident angles. The proposed FSS can better meet the engineering requirements.
The ability to make object invisibility with a cloak that is fitted to all various shape objects is a long-term aim for investigating optical devices. Invisibility cloak with communication ability illustrated so far generally include a conformal elliptical structure hidden an object that has fixed size, so it is inconvenient for the different shape objects. We therefore seek a non-conformal elliptical complementary cloak with arbitrary axial ratio to solve this issue. The complementary cloak is an elliptical structure composed of three regions, which allows for exchange of information with the outside world without “anti-objects” that is difficult to define.
This paper focuses on the efficient design and FPGA realization of CIC based decimation filter structure for WiMAX application. This structure reduces the sampling rate at each section and lower the power consumption in each section with improved magnitude response. The magnitude responses and device utilization of the filter with different combinations considering different stages are estimated and compared with the existing structures. MATLAB Simulink environment is used for design and Xilinx Virtex-V XC5VLX110T-3ff1136 FPGA is utilized for implementation. It is observed from the results that the passband droop and stopband characteristics of this filter structure are improved when the decimation factor of first section is less compared to second section (M1 < M2). On the other hand power consumption of the filter is less when the decimation factor of first section is high compared with second section (M1 > M2). The results show that the passband droop improvement is about 38% and stopband attenuation improvement is of 33% for the decimation factor M = 8.
Ionizing radiation can disturb electrical and electronic devices. These devices need to be tested and qualified to operate under special environment conditions such those present in nuclear or space applications. Radiation effects must be considered when designing systems that must have high mean time between failures and are exposed to radiation. This paper shows how common radiotherapy linear accelerators (LINAC) can be used to characterize the Total Ionizing Dose (TID) effects on electronic devices. This work presents the principal radiation-induced effects on a Raspberry Pi Compute Module board, as good representative of typical Commercial Off-The-Shelf components. The Monte Carlo method used and the procedure for TID characterization are shown.
With the advance of process technology, the power density of chipsets has rapidly increased, which has resulted in thermal issues. Modern mobile devices use a thermal management model (TMM) to solve such thermal issues. In this paper, we propose an adaptive proportional-integral-derivative (PID) controller based on mobile CPU system characteristics. In the proposed method, we dynamically adjust the PID constants according to the thermal characteristics. We evaluate thermal mitigation capability and performance using a commercial smartphone. The results show that our scheme decreases the overall system temperature by 5.13% and simultaneously improves the system performance by 5.51%.
This letter presents the design and fabrication of a five-octave broadband low noise amplifier (LNA) using 0.1-µm GaAs pseudomorphic high-electron mobility transistor (pHEMT) technology. The multi-peaking bandwidth enhancement and noise reduction technique is proposed for a cascode topology to significantly improve the performance of the LNA. The fabricated LNA achieves a −3 dB bandwidth of 1–32 GHz with an average gain of 12.2 dB, an excellent noise figure (NF) of 1.9–2.6 dB, and an output-referred 1 dB compression point (OP1dB) of 10.2–12.7 dBm with good input/output matching over the entire bandwidth. To the best of the authors’ knowledge, these results demonstrate the lowest room-temperature NF ever reported for fully integrated MMIC amplifiers with a bandwidth of 1 to more than 30 GHz.
To obtain actual responses of nonlinear terminations for the transmission lines sag above lossy ground, it imperatively need to build the equivalent circuits of transmission lines sag. In this paper, the multi-conductor transmission lines sag above lossy ground are divided into a sequence of smaller segments, each of which is approximate equal height. Equivalent circuit of the transmission lines sag is composed of each segment in series. And the simplified equivalent circuit of transmission lines sag above lossy ground excited by the external electromagnetic fields is built by combined the neighboring elements. The proposed method is compared with the result obtained by the FDTD method, a good agreement is observed. And the amplitude of the response is less than the results when the transmission lines are considered as the straight lines.
In order to solve the problem of consistency after grouping of silver zinc battery, a multi-step FCM (MSFCM) algorithm is proposed for the separation of silver zinc battery. The method uses the clustering validity function to determine the optimal class number, two times of FCM sorting algorithm in optimal results, obtained classification results of different applications in the battery cycle life. Using the method of dynamic consistency life cycle, attenuation rate decreased significantly in the 30 cycle life test after the capacity decay rate does not exceed the idea of 10%.
In this paper, a compact dual-band bandpass (DB-BPF) with multiple transmission zeros and wide stopband is developed. The DB-BPF consists of a pair of open-ended stub-loaded short-circuited stepped-impedance resonators with easy control of their two fundamental resonant modes. Moreover, multiple geometrical parameters in both the external feeding structure and the internal couplings between neighboring resonators are employed to make the individual control of the two passbands possible. Furthermore, the introduced multiple coupling paths between the resonators produce transversal signal interference which creates multiple transmission zeros. As a result, the selectivity of the passbands is improved significantly, and the stopband of the filter is extended greatly. A DB-BPF with center frequencies of 1.5 GHz and 3.65 GHz, and fractional bandwidths (FBWs) of 5% and 3% is fabricated, and its measured response agrees well with the predicted one.