We analyze the modal gain of Ga(NAsP) multi quantum-well heterostructures pseudomorphically grown on (001) silicon substrate by metal-organic vapor-phase epitaxy. Using the variable stripe length method, we obtain high modal gain values up to 78 cm−1 at room temperature that are comparable to the values of common high quality III-V laser material. We find good agreement between experimental results and theoretically calculated gain spectra obtained using a microscopic model. The results underline the high potential of Ga(NAsP) as an active material for directly electrically pumped lasers on silicon substrate.

This paper presents SiGe-based transmitter and receiver chips for a radio frequency identification (RFID) frontend in the 61-GHz industrial, scientific, and medical (ISM) frequency band. The chips are fabricated in a modern 130-nm SiGe BiCMOS technology with HBTs offering an f T of 250 GHz and f max of 370 GHz. The presented transmitter consists of a fundamental voltage-controlled oscillator (VCO), a power amplifier (PA), lumped element Wilkinson power dividers, and a static divide-by-16 chain for stabilization within a phase-locked loop (PLL). Two variants of the transmitter are fabricated with supply voltages of 3.3 and 5 V, respectively. The transmitters are designed to provide an efficient signal source to supply a passive RFID tag with the maximum allowed 20-dBm effective isotropic radiated power (EIRP) for short-range devices. The 3.3-V transmitter chip achieves a peak output power of 17 dBm, PAE PA of 18.6% and dc-to-RF efficiency of 12.9% (excluding the divider). At 61 GHz, a phase noise of −102 dBc/Hz at 1 MHz offset is achieved. The power consumption for the 5-and 3.3-V transmitter chips is 710 and 482 mW, respectively. The receiver chip is implemented as two Gilbert cell mixers inphase quadrature configuration to compensate for destructive interference that may be caused by varying distance between reader and tag.

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