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A broadband Gilbert downconverter with a miniature phase-inverter rat-race coupler is demonstrated using 0.35µm SiGe BiCMOS technology. By lumped-distributed and band-broadening techniques, a large shrinkage ratio with wide bandwidth of Chebyshev response can be simultaneously attained in the spiral-shape coplanar-stripline phase-inverter rat-race coupler. The area of the demonstrated lumped-distributed phase-inverter rat-race coupler is 0.65×0.65 mm2 and the experimental bandwidth ranging from 2.5 to 12.5 GHz is large enough to cover the UWB bandwidth. As a result, a broadband Gilbert downconverter with the proposed coupler achieves a conversion gain of 11-12 dB, IP1dB of -11 dBm, IIP3 of -1 dBm and noise figure of 16 dB from 3 to 11 GHz. [ABSTRACT FROM AUTHOR]

A broadband Gilbert downconverter with an integrated dual Marchand balun (balanced to unbalanced transformer) is demonstrated by using 0.35 µm SiGe heterojunction bipolar transistor (HBT) technology. A dual Marchand balun consisting of a lower band balun and an upper band balun is employed in the LO stage of the downconverter to maintain balanced LO signals from 1.8 to 36 GHz. The broadband downconverter has peak conversion gain of 3 dB at RF=3 GHz and 3 dB bandwidth of 1.8 to 20 GHz at 3.3 V DC supply. [ABSTRACT FROM AUTHOR]

A 5.7 GHz GaInP/GaAs heterojunction bipolar transistor (HBT) sub-harmonic Gilbert downconversion mixer with octet-phase LO generator is demonstrated. The conversion gain is 15 dB, IP1dB is -13 dBm, IIP3 is 0 dBm, and IIP2 is 24 dBm when the LO power equals 3 dBm. The measured IF quadrature output waveforms indicate that the phase difference between the in-phase and quadrature-phase output channels is only 1.3°. [ABSTRACT FROM AUTHOR]

The first fully integrated GaInP/GaAs heterojunction bipolar transistor (HBT) quadrature voltage controlled oscillator (VCO) using the stacked-transformer LC tank is demonstrated at 5.43–5.31 GHz with low-phase-noise performance. The stacked-transformers are formed by two interconnect metal layers and possess good electrical properties at high frequencies because of the semi-insulating GaAs substrate. The quadrature VCO at 5.38 GHz has phase noise of -127.4 dBc/Hz at 1 MHz offset frequency, output power of -4 dBm and a figure of merit (FOM) -191 dBc/Hz. [ABSTRACT FROM AUTHOR]

A 10 GHz dual-conversion low-IF downconverter using 0.18-µm CMOS technology is demonstrated. The high-frequency quadrature RF and LO1 signals are generated by broadside-coupled quadrature couplers while a two-section polyphase filter is utilised for the low-frequency LO2 quadrature signal generation. As a result, the demonstrated downconverter achieves a conversion gain of 7 dB, IP1 dB of -16 dBm, IIP3 of -5 dBm and noise figure of 26 dB at a 1.8 V supply. The image-rejection ratio of the first/second image signal is 33/42 dB for IF frequency ranging from 10 to 60 MHz, respectively. [ABSTRACT FROM AUTHOR]

An ultra-wideband (UWB) I/Q downconverter with an LR-CR quadrature generator is demonstrated using 0.35 µm SiGe HBT technology. The I/Q outputs of this generator are always in quadrature phase at any frequency while the BJT-type active mixer inherently tolerates much LO power difference for a flat gain response. Consequently, the amplitude imbalance and phase error of the I/Q outputs are less than 1 dB and 2° in the RF frequency range 3–11 GHz. [ABSTRACT FROM AUTHOR]

A 0.18 µm CMOS 5 GHz quadrature voltage-controlled oscillator (QVCO) is demonstrated by using trifilar transformer coupling. The trifilar transformers composed of one primary coil and two secondary coils are used to separate the gate and drain bias for output voltage swing optimisation and also replace a conventional transistor-coupling method for quadrature output generation simultaneously. As a result, the trifilar-coupling QVCO achieves 180.1 dBc/Hz figure of merit (FOM) at the supply voltage of 1.2 V. The on-chip passive single sideband upconversion mixer is also demonstrated to fairly measure the quadrature accuracy of the QVCO. Thus, a 33.7 dB sideband rejection ratio is achieved. [ABSTRACT FROM AUTHOR]

A low-voltage wideband downconverter along with an integrated transformer RF balun using the 2 µm GaInP/GaAs HBT technology is demonstrated. This transformer is a symmetric type and plays a role as a single-to-differential balun. Without the parasitic between the transformer and the substrate, the transformer can work at higher frequencies. This transformer downconverter operates from 1.5 to 14 GHz with around 20 dB conversion gain and 1.8 GHz IF 3 dB bandwidth. The frequency range of the mixing operation is wide and covers the digital video broadcasting via satellite (DVB-S) bands. This mixer is therefore useful for DVB-S applications. [ABSTRACT FROM AUTHOR]

A regenerative frequency divider with a differential transimpedance amplifier (TIA) active load using 0.35 µm SiGe HBT technology is demonstrated. The differential TIA is beneficial for higher frequency and lower sensitivity operation, and the inductive peaking enhances the bandwidth of the output buffer. From the experimental results, the operating frequency ranges from 5 to 27 GHz ( fmax/fmin=5.2) for a supply voltage of 5 V and core power consumption of 49.5 mW. The chip size is 0.86×0.822 mm. [ABSTRACT FROM AUTHOR]

A frequency divider with super-dynamic D-type flip–flop is demonstrated in 2 µm GaInP/GaAs HBT ( fT = 40 GHz) technology. By biasing the HBT devices around the peak transit-time frequency ( fT), the operating frequency of a D-FF with ECNFP (emitter-coupled negative feedback pairs) can be improved. At a supply voltage of 5 V, a divide-by-two function of 9.5 GHz is achieved. [ABSTRACT FROM AUTHOR]

A compact 5.2 GHz upconversion micromixer using the 0.35 µm SiGe HBT technology is demonstrated. A bandpass and area-saving LC current mirror using the active inductor is incorporated to increase the conversion gain. The demonstrated upconverter has conversion gain of -3.5 dB, OP1dB of -10 dBm, and OIP3 of 0 dBm. [ABSTRACT FROM AUTHOR]