## Abstract

In this letter, a <inline-formula> <tex-math notation="LaTeX">$Ka$</tex-math> </inline-formula>-band low error-vector-magnitude (EVM) subharmonically injection-locked frequency-locked loop (SILFLL) in-phase and quadrature (IQ) modulator is proposed using 0.18-<inline-formula> <tex-math notation="LaTeX">$\mu $</tex-math> </inline-formula>m CMOS process. The proposed circuit consists of an SILFLL and four reflection-type modulators. A stacked-boosting technique is employed in the oscillation core to further extend the frequency up to 28 GHz, and a dual-injection technique is employed in the SILFLL to significantly widen the lock range. As the subharmonic number is 3, the measured phase noise at 1-MHz offset and jitter integrated from 1 kHz to 40 MHz are better than <inline-formula> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula>120 dBc/Hz and 95 fs, respectively. Between 26.6 and 28.2 GHz, the proposed SILFLL IQ modulator features an EVM of within 8%, a phase error of 2<inline-formula> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula>, and a magnitude error of 2% for various quadrature amplitude modulations (QAMs), and the modulation can be up to 64-QAM scheme. The work is suitable for a few advanced digital communications due to its high modulation quality.

Original language | English |
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Pages (from-to) | 1-4 |

Number of pages | 4 |

Journal | IEEE Microwave and Wireless Components Letters |

DOIs | |

State | Accepted/In press - 2022 |

## Keywords

- <inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX">$Ka$</tex-math> </inline-formula>-band
- CMOS
- CMOS process
- Frequency locked loops
- Frequency measurement
- Frequency modulation
- Modulation
- Phase measurement
- Phase noise
- digital modulation
- injection lock
- microwave
- millimeter-wave (mm-wave)
- quadrature voltage-controlled oscillator (QVCO)