ADL6010

Data Sheet

Rev. B | Page 18 of 22

Multipoint calibration can be used to further improve accuracy

and extend the dynamic range. The transfer function is now

broken into segments, with each having its own slope and

intercept. Thus, Figure 40 shows the error plot of the same test

device with calibration input points of −28 dBm, −10 dBm, and

+10 dBm. The three point, dual slope calibration results in

tighter error bounds over the high end of the range and extends

the lower measurement range to −30 dBm for ±1 dB error.

and Temperature (−55°C, −40°C, +25°C, +85°C, +125°C) at 10 GHz

Using Three Point Calibration

For the device shown in Figure 40, the change in error with

temperature is very small over the upper 25 dB of the measurement

range, being ±0.4 dB, and widens at lower power levels, reaching

±0.9 dB over the −10 dBm to −20 dBm segment. High volume

production samples may perform better.

For comparison, the three point calibration of a second device

is shown in Figure 41 using the same frequency and calibration

points. This sample has greater dynamic range, and the

temperature dependence of error at lower power levels is

inverted relative to the first device.

Figure 41. 10 GHz Conformance Error and Output Voltage vs. RF Input Power

Figure 42 shows the conformance error at 10 GHz for four

devices at +25°C, −40°C, and +85°C using a three point

calibration at input levels of −28 dBm, −10 dBm, and +10 dBm.

The error plots at each temperature were calculated with respect

to the slope and intercept values extracted from the 25°C line in

each case. This calculation is consistent with a typical production

scenario where calibration at only one temperature is used.

Figure 42 illustrates the various error scenarios possible at low

input levels. The dynamic range of the three point calibrated

devices extends to −30 dBm for ±1.0 dB error at 25°C.

Figure 42. 10 GHz Conformance Error and Output Voltage vs. RF Input Power

4

3

2

1

0

–1

–2

–3

–4

10

1

0.1

0.01

0.001

–55°C

–40°C

+25°C

+85°C

+125°C

15

5

–5

–15

–25

20

10

0

–10

–20

–30

CALIBRATION AT –28dBm, –10dBm, AND +10dBm

4

3

2

1

0

–1

–2

–3

–4

10

1

0.1

0.01

0.001

–55°C

–40°C

+25°C

+85°C

+125°C

15

5

–5

–15

–25

20

10

0

–10

–20

–30

CALIBRATION AT –28dBm, –10dBm, AND +10dBm

4

3

2

1

0

–1

–2

–3

–4

10

1

0.1

0.01

0.001

–40°C

+25°C

+85°C

15

5

–5

–15

–25

20

10

0

–10

–20

–30

CALIBRATION AT –28dBm, –10dBm, AND +10dBm