Novel third-order distortion generator with residual IM2 suppression capabilities

Huang, Wenhu; Sand, R.E.

doi:10.1109/22.739225

Cited by 8 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many early predistortion circuits utilized the nonlinear impedance characteristic of back-to-back diodes [10]- [12], while an active implementation of such a circuit with higher cubing gain using bipolar junction transistor devices was reported in [13]. Such architectures were not considered for the project in [9] as they are not easily implemented in CMOS processes.…”

Section: Prior Art In Cubic-term Generatorsmentioning

confidence: 99%

“…Assuming that the transconductances of the MOS devices can be expressed as a Taylor series (11), the beat-frequency IM2 product voltage at the balun input can be expressed as (12) where represents the differential amplitude of sinusoidal blocker X and represents the load resistor of the circuit input stage. Here, the UMTS TX leakage is modeled as sinusoidal blocker #2 (11) (12) The value of can be found via the Taylor series expansion of the MOS short-channel current (13) [23].…”

Section: Noise In Multistage Cubic-term Generatorsmentioning

confidence: 99%

“…Here, the UMTS TX leakage is modeled as sinusoidal blocker #2 (11) (12) The value of can be found via the Taylor series expansion of the MOS short-channel current (13) [23]. To simplify the notation, the equalities in (14) have been substituted (13) (14) Taking the repeated derivatives of (13) yields the following: The power spectral density (PSD) of the thermal noise of the input devices is evaluated using the MOS long-channel noise model.…”

Section: Noise In Multistage Cubic-term Generatorsmentioning

confidence: 99%

See 2 more Smart Citations

Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers

Keehr

Hajimiri

2009

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

Abstract-Adaptive feedforward error cancellation applied to correct distortion arising from third-order nonlinearities in RF receivers requires low-noise low-power reference cubic nonidealities. Multistage cubic-term generators utilizing cascaded nonlinear operations are ideal in this regard, but the frequency response of the interstage circuitry can introduce errors into the cubing operation. In this paper, an overview of the use of cubic-term generators in receivers relative to other applications is presented. An interstage frequency response plan is presented for a receiver cubic-term generator and is shown to function for arbitrary three-signal third-order intermodulation generation. The noise of such circuits is also considered and is shown to depend on the total incoming signal power across a particular frequency band. Finally, the effects of the interstage group delay are quantified in the context of a relevant communication standard requirement.

show abstract

Section: Prior Art In Cubic-term Generatorsmentioning

confidence: 99%

Section: Noise In Multistage Cubic-term Generatorsmentioning

confidence: 99%

Section: Noise In Multistage Cubic-term Generatorsmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers

Keehr

Hajimiri

2009

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

show abstract

“…The IM produced by APD has a proper magnitude, 180° out of phase in comparison with that generated by the main amplifier. This allows the APD to control the IM3 (third‐order IM) component in the IM generator and the enhanced linearity can then be obtained in the power amplifier design [5–7].…”

Section: Design Theorymentioning

confidence: 99%

Linearity enhanced Doherty power amplifier using analog predistortion

Cho

Lee

2010

Micro & Optical Tech Letters

View full text Add to dashboard Cite

We propose a linearity-enhanced Doherty power amplifier using an analog predistortion (APD) technique, which incorporates an intermodulation (IM) generator. Because the IM generator is configured with antiparalleled diode structure, the resulting Doherty power amplifier behaves differently from a conventional one. Using antiphased IM generated by the hybrid coupler before the auxiliary amplifier, linearity for the whole power amplifier is improved because the IM from the main amplifier can be cancelled out at the combining section. The output power of the proposed Doherty power amplifier is observed 28 dBm at the maximum in measurement, whereas the adjacent channel leakage ratio is 18 dB improved at 5 MHz offset compared with that of the Doherty power amplifier without APD.

show abstract

“…A typical o utput response of an anti-parallel diode pair is given in [7] and shown in To improve the cubic response of diode circuits, a modified anti-parallel diode circuit was proposed in [9] to improve the suppression of the linear term and another circuit topology was proposed in [27] to improve the suppression of the second-order term . Diodes can be used to generate an exponential characteristic, but consideration of higher order term s (which were neglected within these papers) is useful in order to improve cubing accuracy.…”

Section: Rf Rsmentioning

confidence: 99%

CMOS analog cubing circuits for radio-over-fiber predistortion

Shearer¹

View full text Add to dashboard Cite

Novel third-order distortion generator with residual IM2 suppression capabilities

Cited by 8 publications

References 3 publications

Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers

Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers

Linearity enhanced Doherty power amplifier using analog predistortion

CMOS analog cubing circuits for radio-over-fiber predistortion

Contact Info

Product

Resources

About