IEEE Microwave and Wireless Components Letters

We develop a two-dimensional scheme, whose spectral properties exhibit a certain degree of controllability, as an alternative to the classic finite-difference time-domain method. The new approach adopts a nonstandard structure for the spatial operators, whose final form is determined through a consistent error-minimization procedure. It is shown that isotropic improvement of accuracy can be accomp... View full abstract»

The rationale behind several previously reported FDTD formulations for directly implementing fractional-ordered Cole-Cole models is investigated from another perspective. The explicit expressions of their numerical permittivities are derived, respectively, which makes a quantitative comparison of their modeling ability on a Cole-Cole medium possible and verifies the direct validation of these form... View full abstract»

Rational fitting techniques are often used for the macromodeling of linear systems from tabulated S-parameter frequency samples. This letter proposes a modified weighting scheme for the Vector Fitting algorithm that iteratively minimizes the maximum absolute error over the frequency range of interest, rather than the least-squares error. By considering the appropriate error measure in the fitting ... View full abstract»

A novel surface integral equation based algorithm is proposed for accurate inductance and resistance extraction in 3-D interconnects. The surface integral equation is obtained by using the skin-effect cross-sectional approximation of the volumetric current density in the traditional volumetric integral equation. The method allows for substantial reduction of computational complexity in the pertine... View full abstract»

The problem of three transverse cylindrical posts in a rectangular waveguide is analyzed using a numerically efficient technique. It is shown that a relatively large shunt reactance range is achievable compared to that from a single variable-length post. An approximate expression for the series reactance is also reported, allowing the full T-equivalent circuit to be calculated. View full abstract»

A compact wide-band passive equalization design using a stub with defected ground structure is proposed. The proposed design, based on reflections under a slow wave effect, compensates for inter-symbol interference with wide bandwidth, compact size, remarkable compensation capability with few manufacturing limitations, and high design flexibility, compared to previous equalization design. Signific... View full abstract»

A switchable microstrip bandpass filter (BPF) with reconfigurable on-state frequency responses is proposed. The filter consists of a two-pole BPF and two switchable delay lines. The proposed filter features not only switch ability with an on-off ratio of 41.2 dB but also two on-state frequency responses: Chebyshev response and quasi-elliptic-function response. Experiment was carried out to validat... View full abstract»

This letter presents a compact planar tri-band bandpass filter with high selectivity. The proposed filter employs two sets of resonators, i.e., stub-loaded resonators and half-wavelength resonators. The former is designed to operate at the first and third passbands and the latter at the second passband. The passband frequencies can be conveniently tuned to desired values. One set of resonators is ... View full abstract»

A tri-band bandpass filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-band, and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to provide the coupling between the SLRs. The three pass-bands are combined together with... View full abstract»

By the use of screen-printing technique, four kinds of basic structures (outer-frame, U-shaped resonator, modified end-coupled microstrip line, and defected ground structures) are combined to develop a miniature quad-band bandpass filter on a MgTa1.5Nb0.5O6 microwave ceramic substrate. The operating frequencies are designed for the applications of the modern GPS (1... View full abstract»

The characteristics of silicon on insulator MOSFETs are modified to enhance the RF performance by varying channel implants. Without adding new masks or fabrication steps to the standard CMOS process, this approach can be easily applied in standard foundry fabrication. The transconductance, output resistance, and breakdown voltage can be increased by eliminating channel and drain extension implants... View full abstract»

This letter presents high frequency noise measurements carried out for MOSFETs in W-band (75-110 GHz). Because the 50 ¿¿ noise figure of 65 nm node MOSFETs is higher than 10 dB in W-band, pre-matched structures covering the entire band have been developed to reduce the noise figure and to increase the gain. Then, in order to validate the 2 temperatures noise model in W-band, only F50 measurements ... View full abstract»

An AlGaN/GaN HEMT-compatible lateral field-effect diode has been used for zero-bias microwave detector application. Using the versatile fluorine plasma ion treatment technique, we have been able to realize a diode that exhibits strong nonlinearity near zero bias, thus, eliminating DC supplies in microwave detector circuits. The AlGaN/GaN microwave detectors deliver high sensitivity, wide dynamic r... View full abstract»

A 0.5-11 GHz CMOS low noise amplifier (LNA) is proposed, with a new dual-channel shunt technique implemented, where one channel uses inductive-series peaking to provide flat gain over 0.5 to 11 GHz, and another channel adopts resistive feedback to realize wideband input impedance matching. The LNA was fabricated using the TSMC 0.18 ¿¿m CMOS process, achieving a maximum power gain of 10.2 dB. Its i... View full abstract»

A Q-band, Class-E power amplifier has been designed and fabricated in a 0.12 μm SiGe BiCMOS technology. The amplifier was designed for high output power using on-chip power combining networks. It operates respectively from a 1.2 V supply for peak efficiency and a 2.4 V supply for maximum power and occupies an area of 0.801 mm2. A peak PAE of 18% is measured for an output power o... View full abstract»

Two- and three- stage high voltage/high power (HiVP) amplifiers have been designed, implemented, and measured using a 0.12 ¿¿m SiGe HBT process. The HiVP is a circuit configuration that allows for very large output voltage swings, leading to high output power when used in a power amplifier. This letter describes the first implementation of a HiVP circuit using Silicon Germanium (SiGe) Heterojuncti... View full abstract»

In this letter, we present an amplifier module operating at a frequency of 0.48 THz. This represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date. The amplifier demonstrates a peak gain of 11.7 dB measured in a waveguide split-block housing. Sub 50-nm InP HEMT transistors with an estimated f<... View full abstract»

This letter reports power amplifiers for 77-GHz automotive radar applications in a 90-nm LP (low power) 1P6M CMOS technology. The three-stage single-ended PA has a 12.4 dB gain and a +9.1-dBm saturated output power and the two-stage differential PA has a 11.3 dB gain and a +11.4-dBm output power at Pin = 1.9 dBm. This is the first letter to report CMOS PA characteristics over full autom... View full abstract»

This letter presents a multi-level pulse modulated polar transmitter architecture. Compared to a conventional gate-modulated envelope elimination and restoration transmitter, the use of the proposed technique is capable of reducing the in-band quantization noise level. Moreover, the proposed technique can increase the pulse-width modulation sampling frequency by relaxing its resolution requirement... View full abstract»

Waveguide probes are useful for extracting the electric and magnetic properties of material layers, but the accuracy of the results is limited by the accuracy of the theoretical model. Using more modes in the expansion of the waveguide fields produces better results, but the computational cost increases with the number of modes squared. This letter analyzes the dependence of solution accuracy on t... View full abstract»