Abstract
This study presents a voltage-controlled oscillator (VCO) in a cross-coupled pair configuration using a multi-tapped switched inductor with two switch-loaded transformers in 0.5 µm GaN technology. Two switch-loaded transformers are placed at the inner and outer portions of the multi-tapped inductor. All the switches are turned off to obtain the lowest sub-band. The outer transformer with three pairs of switches is turned on alternately to provide three sub-band modes. A pair of switches at the inner transformer provide a high-frequency band. Two switch-loaded transformers are turned on to provide the highest sub-band. Six modes are selected to provide a wide tuning range. The frequency tuning range (FTR) of the VCO is 27.8% from 3.81 GHz to 8.04 GHz with a varactor voltage from 13 V to 22 V. At a 1 MHz frequency offset from the carrier frequency of 4.27 GHz, the peak phase noise is −119.17 dBc/Hz. At a power supply of 12 V, the output power of the carrier at 4.27 GHz is 20.9 dBm. The figure of merit is −186.93 dB because the VCO exhibits a high output power, low phase noise, and wide FTR. To the best of the author’s knowledge, the FTR in VCOs made of GaN-based high electron mobility transistors is the widest reported thus far.
Highlights
A common-gate balanced Colpitts voltage-controlled oscillator (VCO) operated at 6.45–7.55 GHz was fabricated in 0.25 μm GaN high electron mobility transistors (HEMT)
A power VCO based on a T-type lumpedelement feedback delay line topology and Class E power amplifier with a frequency from 9.348 GHz to 9.46 GHz was prototyped with 0.25 μm GaN HEMT on SiC, which has 27.9 dBm Pout and −121.62 dBc/Hz phase noise (PN) at the offset of 1 MHz [10]
We present a VCO in a cross-coupled pair configuration involving a multi-tapped switched inductor with two switch-loaded transformers
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. A common-gate balanced Colpitts VCO operated at 6.45–7.55 GHz was fabricated in 0.25 μm GaN HEMT on silicon carbon substrate with 15% FTR, 2 dBm Pout , and −132 dBc/Hz PN at a 1 MHz offset [8]. A common-source single-end VCO with a feedback network was fabricated using 0.25 μm GaN-on-SiC HEMT technology with 400 MHz FTR, 1.06 dBm Pout , and. A power VCO based on a T-type lumpedelement feedback delay line topology and Class E power amplifier with a frequency from 9.348 GHz to 9.46 GHz was prototyped with 0.25 μm GaN HEMT on SiC, which has 27.9 dBm Pout and −121.62 dBc/Hz PN at the offset of 1 MHz [10]. The lowest PN is −119.17 dBc/Hz at a
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