Apisak Worapishet

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A triple-mode microstrip ring resonator core for the design of bandpass filters is proposed in this paper. It is a modification of the conventional single-mode ring resonator with a pair of open-ended coupled lines and a shunt open stub for a transmission-line path of the ring substituted to form a triple-mode resonator. Since the triple-mode resonator(More)
Recently, a distributed arithmetic (DA) technique has been employed in digital implementation of finite impulse response (FIR) filters, since it can significantly reduce hardware resources at the cost of higher clock frequency. In this paper, we show that the concept of DA can be efficiently exploited in an analogue domain. Specifically, a switched-current(More)
A parallel-coupled microstrip bandpass filter based on the stepped-impedance coupled resonator (SICR) for suppression of harmonic spurious response is presented. The SICR relies upon the incorporation of different stepped impedances for the even and odd propagation modes of the coupled microstrip lines. This is to align the modal parallel resonance(More)
SUMMARY The sub-threshold R-MOSFET resistor structure which enables tuning range extension below the threshold voltage in the MOS-FET with moderate to weak inversion operation is analyzed in detail. The principal operation of the sub-threshold resistor is briefly described. The analysis of its characteristic based on approximations of a general MOS equation(More)
— OPAMP-RC integrators built with linear resistors and capacitors can achieve very high linearity. By means of a switched resistor, tuning of the RC time-constant is possible via the duty-cycle of the clock controlling the switched resistor. This paper analyzes the effect of OPAMP slew rate limitations on the distortion of a switched-resistor lossy OPAMP-RC(More)
The design and measured performance of a 1 to 20 GHz CMOS distributed mixer is presented. The design is realized in a standard 0.25mum process and uses asymmetric coplanar strip (CPS) transmission line interconnects for low loss and small circuit size. The measured response shows conversion gain of 1dB with 7dBm LO power and input return loss better than(More)