Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transformer coupling and its modelling for the flux-ramp modulation of
  rf-SQUIDs   Microwave frequency domain multiplexing is a suitable technique to read out a
large number of detector channels using only a few connecting lines. In the
HOLMES experiment this is based on inductively coupled rf-SQUIDs
(Superconducting QUantum Interference Devices) fed by TES (Transition Edge
Sensors). Biasing of the whole rf-SQUID chain is provided with a single
transmission line by means of the recently introduced flux-ramp modulation
technique, a sawtooth signal which allows signal reconstruction while operating
the rf-SQUIDs in open loop condition. Due to the crucial role of the sawtooth
signal, it is very important that it does not suffer from ground loop
disturbances and EMI. Introducing a transformer between the biasing source and
the SQUIDs is very effective in suppressing disturbances. The sawtooth signal
has slow and fast components, and the period can vary between a few kHz up to
MHz depending on the TES signal and SQUID characteristics. A transformer able
to face such a broad range of conditions must have very stringent
characteristics and needs to be custom designed. Our solution exploits standard
commercial, and inexpensive, transformers for LAN networks used in a suitable
combination. A model that allows to take care of the low as well as of the high
frequency operating range has been developed.

29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph