Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A simple scheme of low phase noise microwave synthesizers based on the
  sub-sampling phase lock loop   In this paper, we demonstrate a simple scheme of 6.835 GHz microwave
frequency synthesizer based on the sub-sampling phase lock loop (PLL)
technique. The application of the sub-sampling PLL is the key to simplify the
architecture of the synthesizer in this scheme. A 100 MHz oven controlled
crystal oscillator (OCXO) with ultra-low phase noise is used as the initial
signal source. Then a dielectric resonant oscillator (DRO) of 6.8 GHz is
directly phase locked to the 100 MHz OCXO utilizing the sub-sampling PLL.
Benefiting from the sub-sampling PLL, the processes of microwave frequency
multiplication and phase lock which are necessary in the development of
microwave synthesizer are greatly simplified. Therefore, the architecture of
the synthesizer is very simple. Correspondingly, the power consumption and cost
of the synthesizer are low. The absolute phase noises of the 6.835 GHz output
signal are measured to be -47 dBc/Hz, -77 dBc/Hz, -104 dBc/Hz and -121 dBc/Hz
at 1 Hz, 10 Hz, 100 Hz and 1 kHz offset frequencies, respectively. he
synthesizer can be used as the local oscillator of the Rb atomic clocks. For
the Rb atomic clocks operated in the continuous or pulsed optically pumped
(POP) mode, Tthe short-term frequency stability limited by the absolute phase
noises of the synthesizer through the intermodulation or the Dick effect is
theoretically calculated to be better than 5.0E10^-14/t^1/2. This low phase
noise microwave frequency synthesizer can be used in other experiments of
fundamental physics measurement.

34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th