Output impedance

About: Output impedance is a research topic. Over the lifetime, 11185 publications have been published within this topic receiving 134949 citations.

22.7-dB Gain $-$ 19.7-dBm $ICP_{1{\rm dB}}$ UWB CMOS LNA

Abstract: A fully differential CMOS ultrawideband low-noise amplifier (LNA) is presented. The LNA has been realized in a standard 90-nm CMOS technology and consists of a common-gate stage and two subsequent common-source stages. The common-gate input stage realizes a wideband input impedance matching to the source impedance of the receiver (i.e., the antenna), whereas the two subsequent common-source stages provide a wideband gain by exploiting RLC tanks. The measurements have exhibited a transducer gain of 22.7 dB at 5.2 GHz, a 4.9-GHz-wide B 3dB, an input reflection coefficient lower than -10.5 dB, and an input-referred 1-dB compression point of -19.7 dBm, which are in excellent agreement with the postlayout simulation results, confirming the approach validity and the design robustness.

Sensorless scheduling of the modular multilevel series-parallel converter: enabling a flexible, efficient, modular battery

Abstract: We present a control approach for the modular multilevel converter (MMC) with series and parallel module connectivity (MMSPC) that provides natural module balancing, reduced conduction losses, and enhanced robustness afforded by the parallel mode. In conventional MMC control, the voltage of each module's storage element has to be measured or estimated to enable the controller to equalize the voltages across all modules. This requirement has been one of the key barriers for MMCs in low and medium power applications. In contrast, we use the parallel connectivity of the MMSPC for module voltage balancing. It also enables robust operation in the presence of battery failure by supporting the module voltage with frequent parallelizations of the residual module capacitance. The parallel connectivity further reduces conduction losses at voltage levels below the system maximum by decreasing the effective source impedance. This approach renders attractive for the first time low and medium power MMC applications as well as MMC-based battery storage. These are illustrated with an experimental MMSPC system comprising eight battery modules that generates high-quality ac output without filtering magnetics.

Active impedance compensation

Abstract: Active impedance compensation is accomplished in a bus system by means of a variable capacitor element associated with a connection circuit between system slave devices and an impedance balanced channel. The variable capacitor elements may be programmed using a control value determined by actively exercising the channel with a telemetry signal and evaluating the resulting signal reflections which are indicative of the impedance discontinuities on the channel.

Improving Load Range of Dual-Band Impedance Matching Networks using Novel Load-Healing Concept

Abstract: A novel and very simple scheme to mend conventional dual-band impedance matching networks is presented. It involves the employment of a load-modifying element (load-healer) so as to extend the range of frequency-dependent complex load that could be matched. Two simple load-healers incorporated in the conventional T-network are used to illustrate the concept. The proposed scheme can be successfully applied in many situations where conventional matching networks are severely limited. Two prototypes operating concurrently at 1 and 2 GHz are designed corresponding to the two types of load-healer. They are implemented on FR4 substrate having a dielectric constant of 4.6, a substrate height of 1.5 mm, and a 35-μm copper cladding. The prototypes exhibit good agreement between their EM simulated and measured results.

Programmable termination circuit and method

Abstract: A semiconductor device is provided which includes: a plurality of termination circuits having a plurality of impedance elements connected to an input/output pad, said termination circuits being controlled by impedance control signals; and a controller for outputting said impedance control signals to adaptively change with changes in characteristic impedance of a transmission line connected to the input/output pad in bi-directional data communication, to adaptively control the plurality of impedance elements in the plurality of input termination circuits for matching the impedance to the characteristic impedance of the transmission line. Each of the plurality of impedance elements is configured in pairs of MOS transistors. The plurality of termination circuits have different impedance values. And each of the impedance elements of the plurality of termination circuits is independently controlled.