ADL6010

Data Sheet

Rev. E | Page 18 of 23

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 43 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.

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

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 43, 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 44 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.

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

Figure 44. 10 GHz Conformance Error and Output Voltage vs. RF Input Power

Figure 45 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 45 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.

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

Figure 45. 10 GHz Conformance Error and Output Voltage vs. RF Input Power