Anritsu K250 User manual

OPERATION AND MAINTENANCE
MANUAL FOR BIAS TEES
1. INTRODUCTION
This manual describes the Model K250 and V250
Bias Tee (Figure 1). It provides specifications and a
list of precautions the user should observe when us-
ing the bias tees.
2. DESCRIPTION
The precision K250 and V250 Bias Tees were de-
signed for applications where both dc and RF signals
must be applied to a device under test. They are par-
ticularly suited for active device measurements. DC
voltages of up to 30 volts at 0.5 amperes may be ap-
plied to test devices with negligible effect on RF per-
formance. Low RF throughline loss (dB) and low re-
turn loss ensure negligible effect on measurements
up to 60 GHz. An RF input dc block isolates the in-
put port from the applied bias voltage.
3. SPECIFICATIONS
Table 2 provides performance specifications.
4. PRECAUTIONS
ANRITSU K250 and V250 Bias Tees are
high-quality, precision laboratory devices and
should receive the same care and respect afforded
other such components. Complying with the follow-
ing precautionary notes will guarantee longer com-
ponent life and less equipment downtime due to con-
nector failure. Also, such compliance will ensure
that RF component failures are not due to misuse or
abuse—two failure modes not covered under the
ANRITSU warranty.
a. Beware of Destructive Pin Depth on Mating
Connectors. Measure the pin depth of the con-
nector that mates with the RF component, before
mating. Use an ANRITSU Pin Depth Gauge
(Figure 2, Table 1) or equivalent. Based on RF
components returned for repair, destructive pin
depth on mating connectors is the major cause of
failure in the field. When an RF component con-
nector is mated with a connector having a de-
structive pin depth, damage will likely occur to
the RF component connector. (A destructive pin
P/N: 10100-00025
REVISION: D
PRINTED: MARCH 2000
COPYRIGHT 1992 ANRITSU COMPANY
490 JARVIS DRIVE l MORGAN HILL, CA 95037-2809
Figure 1. Model K250 Bias Tee

depth has a center pin that is too long in respect
to the connector’s reference plane.)
The center pin on an RF component connector
has a precision tolerance measured in mils
(1/1000 inch), whereas connectors on test de-
vices that mate with RF components may not be
precision types. Their pins may not have the
proper depth. They must be measured before
mating to ensure suitability. When gauging pin
depth, if the test device connector measures out
of tolerance in the “+” region, the center pin is
too long. Mating under this condition will likely
damage the RF component connector. On the
other hand, if the test device connector mea-
sures out of tolerance in the “–” region, the cen-
ter pin is too short. While this will not cause any
damage, it will result in a poor connection and a
consequent degradation in performance.
The pin depth for bias tee models are as shown
below:
K250: 0.000 to –0.005.
V250: 0.000 to –0.003.
b. Avoid Over Torquing Connectors. Over
torquing connectors is destructive; it may dam-
age the connector center pin. Never use pliers to
tighten connectors.
c. Avoid Mechanical Shock. RF components
are designed to withstand years of normal bench
handling. However, do not drop or otherwise
treat them roughly. They are laboratory-quality
devices and, like other such devices, require
careful handling.
d. Keep Bias Tee Connectors Clean. The pre-
cise geometry that makes the RF component’s
high performance possible can be easily dis-
turbed by dirt and other contamination adher-
ing to connector interfaces. When not in use,
keep the connectors covered. Refer to paragraph
5 for cleaning instructions.
5. MAINTENANCE
ANRITSU recommends that no maintenance other
than cleaning be attempted by the customer. The
bias tee should be returned to ANRITSU for repair
and/or service when needed.
The traditional method of cleaning K Connectors
with a cotton swab and alcohol can break the male
connector pin on the precision connectors. The rea-
son: the cotton swab has a larger diameter than the
connector (that is, the area between the inner wall
and the center pin.)
We still recommend using a cotton swab; however,
you need to trim the swab before inserting into the
connector.
Some precautions bias tee:
Use either the finger saver that has been pro-
vided with the bias tee or use a 5 inch-pound
torque wrench when connecting to other de-
vices. No other tools are recommended.
Always spin the coupling nut to tighten con-
nections. Spinning the connector body causes
premature wear to the connector interface.
Do not disturb connector center pin. Improper use
(see above) of a cotton swab or other such probe to
clean the inner connector may cause the center con-
ductor to hinge on its bead and weaken or shear the
internal connection.
2 K/V250 OMM
0
1
2
3
45
1
2
3
4
211 2
Figure 2. Pin Depth Gauge
Model Connector Type Gauging Set Model
V250 V Consult Factory
K250 K 01-162
Table 1. Available Gauging Sets

K/V250 OMM 3
Weight: 57 g (2 oz.) Temperature Range: –0°C to +60°C
Table 2. Performance Specifications, 1 of 2
Specification K250 V250
Frequency Range 0.1 to 40 GHz10.1 to 60 GHz1
Insertion Loss 1.2 dB maximum22.2 dB maximum2
Return Loss 15 dB minimum to 20 GHz
10 dB minimum to 40 GHz 13 dB minimum to 20 GHz
9 dB minimum to 40 GHz
8 dB minimum to 60 GHz
RF Power 1W maximum 1W maximum
DC Voltage 30V maximum 30V maximum
DC Current 0.5A maximum 0.5A maximum
DC Port Isolation 20 dB at 0.1 GHz
40 dB above 0.5 GHz 20 dB at 0.1 GHz 40 dB above 0.5 GHz
RF Connectors Input: K Male
Output: K Female Input: V Male Output: V Female
DC Connector SMC Male SMC Male
1 Usable between 0.04 and 0.1 GHz with degraded performance
2 Typical
Rf
OUT
Rf
IN
DC
IN
Schematic Diagram (K and V Connector Models)

Table 1. Performance Specifications, 2 of 2
OUT
RF IN
BIAS TEE K250
1.15 NOM
0.5 NOM
0.525 NOM
0.100 NOM
0.106 THRU
0.25 NOM
0.25 NOM
0.5 NOM
K or V
MALE
K or V
FEMALE
DC
IN
Outline Drawing (K and V Models; Dimensions in Inches)
0.310 NOM