Differential VCO and frequency tripler using SiGe HBTs for the 24 GHz ISM band

A 77-GHz SiGe frequency multiplier (×18) for radar transceivers

“…4. The differential pair of the input amplifier is driven with high input voltage swing and therefore acts as a limiting amplifier, with ideally square-wave collector currents in T1 and T2, producing an odd number of harmonics in addition to the fundamental wave as proposed in [6]. In a symmetric design of a differential amplifier the even harmonics of the collector currents are in common mode and are not seen in the differential output voltage due to cancellation.…”

A 24‐GHz VCO using active FET frequency doubler in 0.18‐μm CMOS technology

“…In addition, it is so difficult to implement a microwave power amplifier that active multiplier is necessary to be used to enhance the gain of second harmonic. Although many similar architecture had reported in [1,2], but it was rarely used in CMOS process because of power handling capability, Compared with the NMOS-and PMOS-only cross-coupled oscillators in [3], the research shows that by adopting the PMOS-only cross-couple pair to construct the core circuit of the oscillator would achieve a better phase noise performance since the PMOS flicker noise is lower than that of the NMOS. In this article, we propose an 24-GHz VCO implemented in a 0.18-m CMOS technology with good performance of Phase noise.…”

“…In space missions such as Voyager, Galileo, and Cassini, the use of dual-reflector antennas with FSS subreflectors has made it possible to share the main reflector among different frequency bands. Furthermore, the increasing demand on the multifunctional antennas for communication systems has required the development of FSS with multiband characteristics [1]. Therefore, frequency selective surfaces with dual-band and multiband responses have been studied by several researchers [1][2][3][4][5][6][7][8].…”

“…Furthermore, the increasing demand on the multifunctional antennas for communication systems has required the development of FSS with multiband characteristics [1]. Therefore, frequency selective surfaces with dual-band and multiband responses have been studied by several researchers [1][2][3][4][5][6][7][8]. Hill and Munk in [2] used a perturbation technique in a single-band FSS to obtain a single-layer dual-band FSS, but attenuation lower than Ϫ10 dB was obtained.…”

Characterization and modeling of silicon integrated spiral inductors for high-frequency applications

“…Moreover, a limited set of onwafer inductors does not provide enough scalability for intermediate inductance values. Designers usually take advantage of electromagnetic (EM) simulators [15,16] that are highly accurate but also very time-consuming and thus more suitable for design verification rather than optimization. To this aim, simple lumped scalable models are largely employed.…”