New boundary integral equations are proposed for two-port slab waveguides which satisfy single mode condition. The boundary integral equations are combined with the orthogonality of guided mode and non-guided field. They are solved by the standard boundary element method with no use of mode expansion technique. Reflection and transmission coefficients of guided mode are directly determined by the boundary element method. To validate the proposed method, step waveguides for TE wave incidence and triangular rib waveguides for TM wave incidence are investigated by numerical calculations.

An f₀/2f₀ (frequency ratio of two) microstrip diplexer with simple circuit configuration as well as low and wideband insertion-loss characteristics is proposed. It is a parallel combination of a coupled line for f₀ port and a wave-trap circuit composed of a transmission line and an open stub for 2f₀ port. All the lines and stub have a quarter-wave length for f₀. Matching circuits are not needed. Circuit and electro-magnetic simulation results prove that the proposed f₀/2f₀ diplexer exhibits well-balanced properties of insertion loss (IL), IL bandwidth, and isolation, as compared to conventional simple f₀/2f₀ diplexers composed of two wave-trap circuits or two coupled lines. The proposed diplexer is fabricated on a resin substrate in a microstrip configuration at frequencies of f₀/2f₀=2.5/5 GHz. Measured results are in good agreement with simulations and support the above conclusion. The proposed diplexer exhibits ILs of 0.46/0.56 dB with 47/47% relative bandwidth (for f₀/2f₀), which are lower and wider than f₀/2f₀ diplexers in literatures at the same frequency bands.

Aluminum Electrolytic Capacitors are widely used as the smoothing capacitors in power converter circuits. Recently, there are a lot of studies to detect the residual life of the smoothing Aluminum Electrolytic Capacitors from the information of the operational circuit, such as the ripple voltage and the ripple current of the smoothing capacitor. To develop this kind of technology, more precise impedance models of Aluminum Electrolytic Capacitors become desired. In the case of the low-temperature operation of the power converters, e.g., photovoltaic inverters, the impedance of the smoothing Aluminum Electrolytic Capacitor is the key to avoid the switching element failure due to the switching surge. In this paper, we introduce the impedance calculation model of Aluminum Electrolytic Capacitors, which provides accurate impedance values in wide temperature and frequency ranges.

A novel shuffle converter by using 3D waveguide of MCF (multi-core fiber)/SMF (single mode fiber) ribbon fan-in fan-out configuration towards over 1,000 port count optical matrix switch has been proposed. The shuffle converter enables to avoid waveguide crossing section in the optical matrix switch configuration, and the principle device showed sufficient crosstalk of less than -54.2 dB, and insertion loss of 2.1 dB successfully.

In this paper, a compact microwave push-push oscillator based on a resonant tunneling diode (RTD) has been fabricated and demonstrated. A symmetrical spiral inductor structure has been used in order to reduce a chip area. The designed symmetric inductor is integrated into the InP-based RTD monolithic microwave integrated circuit (MMIC) technology. The circuit occupies a compact active area of 0.088 mm² by employing symmetric inductor. The fabricated RTD oscillator shows an extremely low DC power consumption of 87 µW at an applied voltage of 0.47 V with good figure-of-merit (FOM) of -191 dBc/Hz at an oscillation frequency of 27 GHz. This is the first implementation as the RTD push-push oscillator with the symmetrical spiral inductor.

The transition dynamics of a multistable tunnel-diode oscillator is characterized for modulating amplitude of outputted oscillatory signal. The base oscillator possesses fixed-point and limit-cycle stable points for a unique bias voltage. Switching these two stable points by external signal can render an efficient method for modulation of output amplitude. The time required for state transition is expected to be dominated by the aftereffect of the limiting point. However, it is found that its influence decreases exponentially with respect to the amplitude of external signal. Herein, we first describe numerically the pulse generation scheme with the transition dynamics of the oscillator and then validate it with several time-domain measurements using a test circuit.