Two geometrically derived stability parameters, µ′ (or µ) and ν′(or ν), are used to analyze the stability of a two-port network. The magnitudes of both µ′ (or µ) and ν′ (or ν) parameters determine geometrical relations between the stability circle and the unit Smith chart in the ΓS (or ΓL) plane. |µ′| (or |µ|) is defined as the minimum distance from the stability circle to the origin of the unit Smith chart in the ΓS (or ΓL) plane, while |ν′|(or |ν|) is defined as the maximum distance. Moreover, the signs of ν′ (or ν) and µ′ (or µ) parameters determine which region of the stability circle is stable (inside or outside) and whether the stable region includes the origin of the Smith chart, respectively. There are totally 12 situations between the stability circle and the unit Smith chart in the ΓS (or ΓL) plane by using µ′ (or µ) and ν′ (or ν) parameters. This paper classifies 12 situations in the ΓS plane and also presents the corresponding practical two-port networks.

The rate of signal transmission on or between monolithic integrated circuits is limited by the cross-talk and the dispersion due to the wired interconnects. The bandwidth limitations can be overcome by wireless chip-to-chip and on-chip interconnects via integrated antennas. In this work the utilization of the electronic circuit ground planes as radiating elements for the integrated antennas has been proposed. This allows for optimal usage of chip area, as the antennas share the same metallization structure as the circuits. By exciting the interconnects between the patch areas in transmission line modes as well as in antenna modes, the interference between signals from circuit to circuit and antenna excitation signals is minimized. This has been achieved by inserting a transformer in the antenna feeding network. Examples of possible antenna and feeding structures have been investigated numerically. Scaled prototypes of the integrated antennas have been manufactured and measured.

This paper describes some key points of a new tool being currently developed by Eurocontrol for the assessment of air traffic control (ATC) multisensor trackers performance. It summarizes the algorithmic foundations of the high-accuracy trajectory reconstruction process used to obtain reference trajectories from recorded measures. These trajectories will serve as a reference for the evaluation of the accuracy of ATC data processing centers. The performance of the system is illustrated with some reconstruction experiments on synthetic and real data.

Metamaterials made of exclusively metallic cut wire pairs have been experimentally demonstrated to exhibit a negative refractive index at optical frequencies. However, other related works on slightly different wire and plate pairs have not shown a negative index. In this paper, we present the analogy between previously reported S-shaped metamaterials and asymmetric cut wire pairs by a simple unifying approach. These two structures present a negative index for some geometrical configurations. Using simulations and experimental measurements in the microwave domain, we investigate the material properties of the last structure. Applying the inversion method from transmission and reflection responses, we show that a negative index is exhibited due to simultaneous negative permittivity ε and permeability μ. A negative index n is experimentally verified in a bulk prism engineered by stacking several layers of the metamaterial.

This paper describes the analysis and the design of an integrated antenna on 0.13 µm SiGe BICMOS technology. A non-resonant dipole antenna integrated on SiGe is electromagnetically coupled to a radiating element reported on a printed circuit board (PCB) substrate. This integrated solution, also compatible with system in package (SIP) concept, provides significant improvements with respect to direct System On Chip (SoC) integration. The main objective of this SIP antenna lies on the optimization of integrated millimeter wave front-ends modules, considering the immediate antenna environment (especially the lossy substrate and technological dielectric/metallic levels), in order to achieve performances compatible with short range radar specifications at 79–81 GHz. One solution, using a RT/Rogers Duroid 6006 PCB (er = 6, thickness h = 127 µm), is presented, providing a 2.93 dBi gain, and 45% radiation efficiency antenna.

Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids is proposed in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan and Nikookar (2007). However, the work in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan and Nikookar (2007) considers a free space propagation channel model with no treatment of the frequency dependence of the path loss. In this paper, we broaden the study by taking into consideration a frequency-dependent path loss environment. The novelty of the work is in the investigation of the effect of frequency dependency of the path loss on the performance of interference mitigation schemes.

This paper presents a new planar particle that shows negative effective permittivity under irradiation by an electromagnetic wave. The mutual coupling between the couples of these particles is studied in particular. The response of this particle sensitive to an electric field is strongly anisotropic. The particle is aimed to be used to compose an isotropic epsilon-negative metamaterial in two forms. First, a unit cell of the metamaterial consists of a cube bearing six particles on its faces, located with specific orientations. The experiments showed that this unit cell is suitable for manufacturing an isotropic epsilon-negative metamaterial obtained by arranging these cells in a 3D cubic periodic system. The second form of an epsilon-negative metamaterial with an isotropic response consists of the planar particles themselves, distributed quasi-randomly, composing a 2D system and/or of particles placed in spherical shells and distributed fully randomly in a hosting material forming a 3D system. The isotropy of these systems was verified by measurements in a rectangular waveguide.

Metamaterial transmission lines can be realized as a combination of right- and left-handed transmission line (TL) sections exhibiting positive and negative dispersion. This approach gives additional degrees of freedom for improving the performance of microwave devices. Artificial right- and left-handed sections, which are based on lumped-element unit cells consisting of inductance and capacitances (LC-cells), are used. This makes it possible to decrease dimensions of the devices drastically. Furthermore, using variable capacitors in LC-cells allows designing tunable devices. This paper presents the results of design, numerical simulation, and experimental investigation of a tunable rat-race ring and free-of-spurious response dual-band filter manufactured as integrated ceramic multilayer circuits based on low-temperature co-fired ceramics. Commercial semiconductor varactors have been used as tunable components.

A new type of spectrum analyzer using RF interferometry is presented. The stationary wave integrated Fourier transform spectrometer is dedicated to the measurement of transient wideband signals. The spectrometer is mobile and cheap. It consists of spatial samplers placed along a waveguide ended by a short circuit. The standing wave caused by the short circuit is sampled and the spectrum is obtained by an FFT computation. A 0.3–5 GHz analyzer was built as a proof-of-principle demonstration and an application to RF dosimetry is shown.

To achieve a high IIP2 level on a mixer, static calibration techniques have been developed. Most of them are based on an intentional introduction of a calibrated mismatch in the structure of the mixer. They are performed at production stage. It is also possible to automate them but their activation is strongly limited in portable devices because of system restrictions. Furthermore, IIP2 is sensitive to system variations, thereby degrading the calibration operation. The challenge is so to make the calibration system dynamic, i.e. performing an online calibration. This paper presents a perturbance-based algorithm as part of an automatic calibration system to track the optimum IIP2 level. Measurements validate the algorithm behavior and indicate the feasibility of using it in a complete calibration system for a future on-chip implementation.

A fast, yet unconditionally stable, solution of time-domain electric field integral equations (TD EFIE) pertinent to the scattering analysis of uniformly meshed and/or periodic conducting structures is introduced. A one-dimensional discrete fast Fourier transform (FFT)-based algorithm is proffered to expedite the calculation of the recursive spatial convolution products of the Toeplitz–block–Toeplitz retarded interaction matrices in a new marching-without-time-variable scheme. Additional saving owing to the system periodicity is concatenated with the Toeplitz properties due to the uniform discretization in multi-level sense. The total computational cost and storage requirements of the proposed method scale as O(Nt2Nslog Ns) and O(Nt Ns), respectively, as opposed to O(Nt2Ns2) and O(NtNs2) for classical marching-on-in-order methods, where Nt and Ns are the number of temporal and spatial unknowns, respectively. Simulation results for arrays of plate-like and cylindrical scatterers demonstrate the accuracy and efficiency of the technique.

This work presents the design, fabrication, and test of X-band and 2–18 GHz wideband high-power single pole double throw (SPDT) monolithic microwave integrated circuit (MMIC) switches in microstrip gallium nitride (GaN) technology. Such switches have demonstrated state-of-the-art performances and RF fabrication yields better than 65%. In particular, the X-band switch exhibits 1 dB insertion loss, better than 37 dB isolation, and a power handling capability better than 39 dBm at a 1 dB insertion loss compression point; the wideband switch shows an insertion loss lower than 2.2 dB, better than 25 dB isolation, and an insertion loss compression of 1 dB at an input drive higher than 38.5 dBm in the entire bandwidth.

In millimeter-wave CMOS circuits, a balun is useful for connecting off-chip single-end devices and on-chip differential circuits to improve noise immunity. However, an on-chip balun occupies a large chip area. To reduce the chip area required for the on-chip balun, a new rat-race balun using a rewiring technology with a wafer-level chip-size package (W-CSP) is proposed. The W-CSP balun occupies no area in a die because it is placed over integrated circuits. In the proposed balun, an S-shaped structure is adopted in order to directly connect the balun to differential GSGSG pads on a chip with a small area. The S-shaped W-CSP balun was fabricated on a silicon-on-insulator (SOI) substrate. The core area of the S-shaped rat-race balun is 480×735 µm, which is 22.4% that of a square rat-race balun. As a result of measurement, we found that the minimum insertion loss is 1.4 dB and the operating frequency ranges from 40 to 61 GHz.

Orthogonal frequency division multiplexing (OFDM) waveforms offer strong advantages for integrated communication and radar systems. However, they exhibit inherent high-range sidelobes after matched filtering when standard communication constellation symbols are used for the coding of the carriers. Consequently, they require filtering at the receiver that can serve for sidelobe suppression in order to avoid target masking. However, unmasking is not the only concern; it is crucial to evaluate the filtering scheme both in terms of sidelobe suppression capability and in terms of output signal-to-noise ratio. This last criterion is essential when aiming at also detecting weaker reflections. In this paper the theoretical performance of the reiterated filtering technique based on linear minimum mean square error (LMMSE) is derived and compared to the matched filter. The unmasking capabilities are relevant, but also output power figures. Complex-valued filter output peaks are also evaluated and compared to the matched filter output peaks. Moreover, the performance of reiterated LMMSE is evaluated for OFDM communication-encoded radar waveforms.