Citation: |
Huang Jiwei, Wang Zhigong, Li Kuili, Li Zhengping, Wang Yongping. A wide-band low phase noise LC-tuned VCO with constant KVCO/ωosc for LTE PLL[J]. Journal of Semiconductors, 2012, 33(2): 025008. doi: 10.1088/1674-4926/33/2/025008
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Huang J W, Wang Z G, Li K L, Li Z P, Wang Y P. A wide-band low phase noise LC-tuned VCO with constant KVCO/ωosc for LTE PLL[J]. J. Semicond., 2012, 33(2): 025008. doi: 10.1088/1674-4926/33/2/025008.
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A wide-band low phase noise LC-tuned VCO with constant KVCO/ωosc for LTE PLL
DOI: 10.1088/1674-4926/33/2/025008
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Abstract
A wideband LC-tuned voltage-controlled oscillator (LC-VCO) applied in LTE PLL frequency synthesizers with constant KVCO/ωosc is described. In order to minimize the loop bandwidth variations of PLL, a varactor array is proposed, which consists of a series of differential variable capacitor pairs and a series of single-pole double-throw (SPDT) switches to connect Vtune or VDD. The switches are controlled by switching bits. With this scheme, the ratio of KV= ∂ Cvar/∂ Vtune and the capacitance value of the capacitor array maintains relatively constant; furthermore, the loop bandwidth of the PLL fluctuation is suppressed. The 3.2-4.6-GHz VCO for multi-band LTE PLL is fabricated in a 0.13-μ m RF-CMOS process. The VCO exhibits a maximum variation of KVCO/ωosc of only ±4%. The VCO also exhibits a low phase-noise of -124 dBc/Hz at a 1-MHz offset frequency and a low current consumption of 18.0 mA with a 1.2-V power supply.-
Keywords:
- voltage-controlled oscillator,
- loop bandwidth,
- LTE,
- KVCO,
- low phase noise
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References
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] -
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