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| * Things need to be evaluated before building it | * Things need to be evaluated before building it. i. Determination of whether ROS-102-191 meets the specification in phase noise. i. Identification of where the dominant noise sources are. i. Identification of where the frequency hop comes from. |
Low Noise VCOs
Descriptions
Low phase noise, a center frequency of 80 MHz, actuation range of several 100 kHz, aaa dBm output
Prototype model
Designed by Y. Enomoto (2018), inspired by LIGO low noise VCOs. JGW-D1808968
Noise performance
Worse than the specification for the non-divided phase noise (klog 7425) at 1 and 10 kHz. See the table below.
- Most of the RF components are not secured to the chassis in order to allow for the quick implementation. This may cause undesired acoustic coupling.
Frequency [Hz]
Measured Frequency noise [Hz/Hz^1/2]
Equivalent Phase noise [dBc/Hz]
ROS-102-919 specification w/o frequency division [dBc/Hz]
0.01
5
51
--
0.1
0.4
9
--
1
0.1
-23
--
10
0.05
-49
--
100
0.05
-69
--
1,000
0.05
-89
-98
10,000
0.03
-113
-123
100,000
--
--
-143
Tuning Range
Linear range of 0.8 to 2.8 V achieved (klog 6544, klog 6638). This is smaller than the expected range of 0-5 V.
- Resulting frequency showed some kind of hops, limiting the linear range. No clear explanation exists at the moment.
Tuning sensitivity of 0.42 MHz/V is achieved (klog 6544). This is consistent with the specification of ROS-102-919 whose sensitivity is 4.5 MHz/V typ.
Endeavour model
- Sophisticated version of the prototype model.
- Things need to be evaluated before building it.
- Determination of whether ROS-102-191 meets the specification in phase noise.
- Identification of where the dominant noise sources are.
- Identification of where the frequency hop comes from.
Bill of Materials
Description
Part number
Manufacture
Notes
Price/each
Seed VCO
ROS-102-191 (with eval.board TB-10)
Minicicruits
center freq. 100 MHz
RF amp for VCO output
LNBA-0-13-BJ-100-15
Wenzel
RF amp for LO
LNBA-10-23-AE-100-15
Wenzel
+23 dBm output
RF amp for the output signal
LNBDA-2-26-AC-AE-100-15
Wenzel
+26 dBm output
Frequency divider
LNFD2-10-100-13-1-13-15
Wenzel
factor of 10
Low noise Mixer
LNMX-X-X-X
Wenzel
no attenuation
1U Chassis for RF
JGW-D1706470-v1
AEL
Aluminum plates for heat sink
needs to be designed
Low noise power unit for RF
Ceramic capacitors for noise reduction
SMA barrel connectors
SMA right angle connectors