Effects of substrate on phase-noise of bipolar voltage-controlled oscillators

Author(s):  
A. Tasic ◽  
W.A. Serdijn
Author(s):  
Pedro Pereira ◽  
Fábio Passos ◽  
M. Helena Fino

Voltage-Controlled Oscillators (VCOs) are widely used in wireless transceivers. Due to the stringent specifications regarding phase-noise, LC-VCOs are usually adopted. The need for maximizing phase-noise as well as minimizing the power consumption makes imperious the adoption of optimization-based design methodologies. For the optimization of the LC-VCO characteristics, special attention must be paid to the integrated inductor design, since its quality factor may have a strong influence in the LC-VCO phase-noise. Furthermore, designers must ensure that the higher limit of VCO operating frequency is sufficiently below the inductor resonant frequency. In this chapter, a study on the influence of the quality factor of the inductors on the LC-VCO overall behavior is presented. Then, optimization of integrated inductors by exploring the inductor geometric layout is presented. Finally, results obtained for the design of an LC-VCO in 130nm Technology using a previously optimized inductor are presented.


2021 ◽  
Vol 11 (21) ◽  
pp. 9815
Author(s):  
Vladimir Ulansky ◽  
Ahmed Raza ◽  
Denys Milke

Negative differential resistance (NDR) is inherent in many electronic devices, in which, over a specific voltage range, the current decreases with increasing voltage. Semiconductor structures with NDR have several unique properties that stimulate the search for technological and circuitry solutions in developing new semiconductor devices and circuits experiencing NDR features. This study considers two-terminal NDR electronic circuits based on multiple-output current mirrors, such as cascode, Wilson, and improved Wilson, combined with a field-effect transistor. The undoubted advantages of the proposed electronic circuits are the linearity of the current-voltage characteristics in the NDR region and the ability to regulate the value of negative resistance by changing the number of mirrored current sources. We derive equations for each proposed circuit to calculate the NDR region’s total current and differential resistance. We consider applications of NDR circuits for designing microwave single frequency oscillators and voltage-controlled oscillators. The problem of choosing the optimal oscillator topology is examined. We show that the designed oscillators based on NDR circuits with Wilson and improved Wilson multiple-output current mirrors have high efficiency and extremely low phase noise. For a single frequency oscillator consuming 33.9 mW, the phase noise is −154.6 dBc/Hz at a 100 kHz offset from a 1.310 GHz carrier. The resulting figure of merit is −221.6 dBc/Hz. The implemented oscillator prototype confirms the theoretical achievements.


2018 ◽  
Vol 72 ◽  
pp. 120-125
Author(s):  
Ihsan F.I. Albittar ◽  
Hakan Dogan ◽  
Mehmet T. Ozgun

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