Input 3rd Order Intercept Point Research Articles

A 1.5-V Current Mirror Double-Balanced Mixer With 10-dBm IIP3 and 9.5-dB Conversion Gain

This brief presents the design of a double-balanced mixer for linearity-stringent communication systems. The pro- posed mixer is based on a current-mirror structure embedded with a switching pair. By utilizing the linear duplication characteristic of current mirrors, an improved linearity is achieved. The mixer is designed and fabricated in 0.18-μm 1P6M radio-frequency CMOS process, operating in the frequency band from 0.5 to 3 GHz. Measurement results indicate a peak conversion gain of 9.5 dB, a high input 3rd order intercept point (IIP3) of 10 dBm and a moderate noise figure (NF) of 16.5 dB. In addition, due to the folded structure, the mixer can be applicable in low-supply-voltage applications. The whole mixer has a compact die area of 0.1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and the power dissipation is 5.4 mW under 1.5-V supply voltage.

Effect of collector bias current on the linearity of common-emitter BJT amplifiers

Using a Volterra series, an explicit formula is derived for the connection between input 3rd-order intercept point and collector bias current (ICQ) in a common-emitter bipolar junction transistor amplifier. The analysis indicates that the larger ICQ is, the more linear the amplifier is. Furthermore, this has been verified by experiment. This study also integrates a method called dynamic bias current for expanding the dynamic range of an LNA (low noise amplifier) as an application of the analysis result obtained above. IMR3 (3rd-order intermodulation rate) is applied to evaluate the LNA's performance with and without adopting this method in this study.

5.8-GHz merged LNA-mixer with on-chip balun

In this paper, the design and application of an on-chip transformer balun for RFIC is presented. Single-ended primary and differential secondary are constructed without using three individual windings for simple layout. Besides, this new topology has the same physical common visual ground point for second winding, which eliminates imbalance due to the potential difference at the ground from a conventional trifilar. Furthermore, this new on-chip balun is successfully applied to the integration of a 5.8-GHz low-noise amplifier (LNA) mixer implemented on SiGe 0.35-μm BiCMOS process then achieves 4.15-dB noise figure (NF), 34.61-dB conversion gain, and a −9.5-dBm input 3rd-order intercept-point with low power consumption of 9 mW. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 508–511, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21394

A 5.2-GHz low-power low-noise amplifier using inGaP-GaAs HBT technology

A 5.2-GHz monolithic low-power low-noise amplifier (LNA) with a quasi-cascode configuration using InGaP-GaAs HBT technology is reported for the first time. A state-of-the-art noise figure of 2.39 dB at 5.2 GHz is obtained among all bipolar LNAs with a fully on-chip input-matching network. The input return loss is −32 dB with a voltage gain of 27 dB at 5.2 GHz. An input 1-dB compression point (P1dB) and an input 3rd-order intercept point (IIP3) of −14 and −5 dBm are also achieved, respectively. This circuit consumes only small dc power of 6 mW. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 425–427, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20843

A high-linearity micromixer for 5-GHz-band WLAN applications using 0.35-?m SiGe BiCMOS technology

In this paper, a down-conversion double-balanced micromixer with very good linearity for 5-GHz-band WLAN applications using 0.35-μm SiGe BiCMOS technology is presented. Good conversion gain of 7.3 dB, LO-RF isolation of 50 dB, LO-IF isolation of 45 dB, and RF-IF isolation of 28.5 dB are achieved at measurement condition of RF frequency of 5.2 GHz, LO frequency of 4.9 GHz, IF frequency of 0.3 GHz, and supply voltage of 3 V. In addition, very good linearity performances, that is, an input 1-dB compression point (P1dB) greater than 0 dBm, and an input 3rd-order intercept point (IIP3) of 0.5 dBm were also achieved. The single-to-differential input stages in the RF and LO ports eliminate the need for common-mode rejection. The micromixer consumes 15.6-mW power and occupies an area of only 660 × 420 μm, excluding the test pads. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 499–502, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20863

An InGaP‐GaAs HBT low‐noise amplifier for 2.4/5.2/5.7‐GHz WLAN applications

AbstractA 2.4/5.2/5.7‐GHz triple‐band low‐noise amplifier (LNA) achieved by switching between different base bias currents (IB) using InGaP‐GaAs HBT technology is reported for the first time. Transducer gains (S21) of 14.6 and 11/9.5 dB, input return losses (S11) of −18.7 and −21.0/−11.5 dB, output return losses (S22) of −20 and −22.7/−24.9 dB, reverse isolation (S12) of −50.5 and −44.4/−44.4 dB, and noise figures of 3.35 and 2.54/2.71 dB were achieved at 2.4 and 5.2/5.7 GHz, respectively. The input 1‐dB compression point (P1dB) and input 3rd‐order intercept point (IIP3) of −8.5 and −1 dBm, respectively, were also achieved at 5.2 GHz. The power consumptions are only 7.6 and 3.6 mW for the 2.4‐ and 5.2/5.7‐GHz bands, respectively. The LNA only occupies an area of 300 × 500 μm, excluding the test pads because only one inductor is used. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 539–542, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20528