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This paper presents a novel ultra low jitter phase‐locked loop (PLL) circuit architecture for RF Sampling Transceiver. The programmable frequency divider with duty cycle expansion and the new phase frequency detector and charge pump circuit are used to solve the problem of voltage domain conversion of narrow pulses in the traditional high‐performance charge pump PLL structure. The traditional structure degrades charge pump linearity and noise, thus deteriorating overall jitter performance. Furthermore, voltage‐controlled oscillator uses the dual core structure and the second harmonic suppression technology, combined with the proposed new switching capacitor structure, and achieves −139.3 dBc/Hz phase noise at the 1 MHz frequency offset of the 5.2 GHz carrier under the open loop state. The PLL implemented in a standard Taiwan Semiconductor Manufacturing Company 28 nm process occupies a core area of 0.4 mm2 and generates a frequency ranging from 4 to 5.2 GHz using 50 MHz oscillator input, the power consumption is 40 mW. It achieves 74.8 fs root‐mean‐square jitter integrated from 10 KHz to 30 MHz. When the PLL output is divided by 2, the output phase noise at 1 MHz frequency offset is −125.75 dBc/Hz, and the PLL FoM is −246. [ABSTRACT FROM AUTHOR]

A low‐noise fully‐integrated charge‐pump phase‐locked loop (CPPLL) for 5G applications is presented in this letter. The PLL architecture includes a phase and frequency detector (PFD), a charge pump (CP), a low‐pass filter (LPF), a voltage‐controlled oscillator (VCO), and a programmable divider. To achieve low phase noise, class‐C VCO, TSPC logic, and other methods are employed in the PLL circuit design. Fabricated in 65 nm technology, the PLL measures a tuning range of 5.91–8.94 GHz. The minimum and maximum measured phase noise are −125 dBc/Hz and −116.6 dBc/Hz @1 MHz. The size of CPPLL core area is 0.8 mm by 0.95 mm without the pads while having a 50‐mW power consumption. [ABSTRACT FROM AUTHOR]

For this task, an improved phase locked loop (PLL) was developed using a more sophisticated phase‐frequency detector with multiband flexible dividers that provide enhanced frequency resolution, a better spectrum, and a better output signal. Great timing jitter was the problem for the old PLL designs because of the unbalanced frequency transfer function caused by the voltage‐controlled oscillator and noise introduced by increases in supply voltage. A new design was suggested for the phase‐frequency detector (PFD) such that PLL lock times are reduced while maintaining a low level of phase jitter. This way, they used fewer transistors, used less power, and had lower propagation holdup and smaller size compared to static PFDs. Additionally, forward ring voltage‐controlled oscillator may improve the resolution of frequency and phase variation errors owing to supply noise by balancing driving force ratios in the feed‐forward and feedback paths. Additionally, there is a dynamic sense flexible divider with several bands for separating special divisions (divide‐by‐47 and divide‐by‐48) that lacks a few extra flip‐flops which save considerable power and improves the frequency difficulties of the multi‐band divider. The advanced phase locked loop (ADPLL) has integrated phase and frequency errors, where the ADPLL excels. The supply noise is decreased by three reference clock cycles and the effect is that the measurement of jitter is better. Advanced Phase Locked Loop oscillates at frequencies ranging from 500 MHz to 4 GHz. A root mean square jitter of 1.29 ps is observed at 1 GHz. Our PLL is rated at 92.1‐μW, with power used at 0.31 mW/GHz. The aim of this article is to design a 180 mm CMOS‐based PLL circuit with a 400 MHz clock and a 0.65 V supply at a fast, dynamic phase frequency detector for resolution and stability. [ABSTRACT FROM AUTHOR]

This paper presents a fully integrated analog phase‐locked loop (PLL) fractional‐N frequency synthesizer for 5G wireless communication and Internet‐of‐Everything (IoE) applications. To demonstrate the effectiveness of this frequency synthesizer, we apply it to three wireless communication standards. Contrary to using Verilog or VHDL to implement the programmable frequency divider, we propose a new approach in the transistor level with a new divide‐by‐2/3 circuit, dynamic asynchronous resettable D and JK flip‐flops, and the OR & AND gates to customize the divider for low‐power, low‐jitter, and fast‐lock time applications. In addition, we have designed a new frequency phase detector (PFD) to overcome the dead region issue. An ultra‐low phase noise and low‐power voltage control oscillator (VCO) is exploited from our previous work with the flicker noise corner frequency around 10 kHz to achieve the lowest possible phase noise. The implementation is done in 180‐nm standard CMOS technology. It covers two frequency ranges including 2.4 to 2.48 GHz and 5 to 5.825 GHz for these wireless communication standards. According to simulations in the worst case, the lock time, rms‐jitter, in‐band fractional spur, power consumption, and jitter‐power figure‐of‐merit of the frequency synthesizer is 18 μs, 56 fs, −63 dBc, 4 mW, and −259, respectively. [ABSTRACT FROM AUTHOR]

A 2 GHz sub‐harmonically injection‐locked phase‐locked loop (SILPLL) with a self‐aligned injection window is presented. The SILPLL adopts a mixer‐based self‐align technique to automatically adjust the injection timing, overcoming the speed limitation of the phase detection. Circuit techniques such as a symmetrical mixer and a V/I converter with mismatch cancellation are adopted to improve injection timing accuracy. Fabricated in a 180 nm CMOS technology, the SILPLL exhibits −127 dBc/Hz phase noise at 1 MHz offset and draws 6.9 mA current from a 1.8 V power supply. The measured root‐mean‐square jitter integrating from 1 kHz to 40 MHz is 214 fs and the reference spur is −61 dBc. [ABSTRACT FROM AUTHOR]

A phase-locked loop (PLL) architecture based on a 2D phase comparator matrix is introduced. In its general form, multiple phases of the input reference clock are compared with multiple phases of the feedback clock, allowing for wider bandwidth (BW) and lower phase noise generation of the PLL. Based on matrix phase detector architecture, a 6.25 GHz PLL achieving 5 GHz BW and exhibiting 55 fs-rms jitter is designed in 28 nm CMOS bulk technology. [ABSTRACT FROM AUTHOR]