A 2 GHz direct-conversion WCDMA modulator in 0.25 μm CMOS

Brenna, G.; Tschopp, David; Pfaff, D.; Huang, Qiuting

doi:10.1109/isscc.2002.993027

Cited by 4 publications

(3 citation statements)

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“…The HBT devices were operated in the ON state when the control voltage is high and the OFF state when the control is low. From (7), the transmission coefficient of the BPSK modulator can be expressed as (8) where is the input reflection coefficient of the HBT at VN port and is the input reflection coefficient of the HBT at VP port. Let us assume that an amplitude imbalance of 3 dB and a phase imbalance of 5 are included in Lange coupler.…”

Section: A Bpsk Modulatormentioning

confidence: 99%

“…Some MMW vector signal measurements can be found in [3] and [4], which demonstrated a vector signal characterization system with error vector magnitude (EVM) and adjacent channel power ratio (ACPR) measurement results for a power amplifier module at 38 GHz. EVM measurements and direct IQ modulator design issues were reported in the microwave range [8], [9]. For a real digital modulated signal coming from an IQ modulator, the amplitude and phase states are time-variant.…”

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confidence: 99%

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Broad-band HBT BPSK and IQ modulator MMICs and millimeter-wave vector signal characterization

Chang

Huang

Wang

et al. 2004

IEEE Trans. Microwave Theory Techn.

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Reflection-type binary phase-shift keying and in-phase and quadrature modulator monolithic microwave integrated circuits (MMICs) are reported in this paper. These MMICs are fabricated by 1-m HBT process and evaluated successfully under vector signal characterization. A cold-mode HBT device model with varying bias conditions is proposed, which is suitable for millimeter-wave circuit design and simulation. The analysis and design equations of imbalance effects for the reflection-type modulators are also presented. These MMICs demonstrate measured error vector magnitude of less than 12%, a carrier rejection of better than 15 dB, and an adjacent channel power ratio of better than 21 dBc from 50 to 110 GHz.

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Section: A Bpsk Modulatormentioning

confidence: 99%

mentioning

confidence: 99%

Broad-band HBT BPSK and IQ modulator MMICs and millimeter-wave vector signal characterization

Chang

Huang

Wang

et al. 2004

IEEE Trans. Microwave Theory Techn.

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“…Furthermore, the two sets of mixers and respective LO synthesizers lead to complex and area/power inefficient designs [2]- [5]. On the other hand, direct conversion transmitters do not require any image reject filter, but they suffer from LO leakage due to dc offset and I/Q mismatch, thus degrading the signal spectrum and the error vector magnitude (EVM) [6], [7].…”

Section: Introductionmentioning

confidence: 99%

A Linear $\Sigma$–$\Delta$ Digital IF to RF DAC Transmitter With Embedded Mixer

Taleie

Copani

Bakkaloglu

et al. 2008

IEEE Trans. Microwave Theory Techn.

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A noise-shaped direct digital IF to RF (DIF2RF) DAC with embedded upconverter mixer is presented. The digital IF signal is noise shaped by a bandpass 6-1 modulator with 1-bit IF output followed by a semidigital finite impulse response (FIR) filter. The current mode FIR filter combines scaled values of the local oscillator (LO) signal for performing reconstruction filtering and upconversion in a single module. The DIF2RF design modulates the digital IF signal with a digital LO signal. This topology eliminates the transconductance nonlinearity of conventional mixers and is inherently linear due to single-bit digital IF input. The presented architecture reduces clock jitter sensitivity of 1-bit DACs by masking IF clock transitions with LO signals. A prototype of the DIF2RF DAC is designed and fabricated in a five-layer metal 0.25-m digital CMOS process. The architecture can be used in low-power software-defined digital-IF transmitters. The DIF2RF DAC consumes 49 mA from a 2.5-V supply, achieving 64.7-dBc third-order intermodulation at 1.03 GHz with a spurious-free dynamic range of 72 dB in a 15-MHz bandwidth.

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