Circuit Note

CN-0523

analog.com

Rev. 0 | 6 of 8

Figure 15. ADM7171 Configuration for a 3.8 V Output

COMMON VARIATIONS

The HMC451 can be used as an alternative power amplifier for

the 5.8 GHz ISM band. Compared to HMC407, this device offers

slightly higher gain (S21) and lower input return loss (S11) at the

cost of having a lower 1 dB compression point, output return loss

(S22), saturation power, and noise figure.

The ADT6402 can also be used as the temperature switch. This

device is pin-compatible and shares the same specifications as the

ADT6401, but has an active-low output and requires an inverting

buffer.

Similar amplifier designs for transmitting signals in the 433.92 MHz,

915 MHz, and 2.45 GHz ISM bands are available. For more infor-

mation, refer to the CN0551, CN0522, and CN0417 circuit notes,

respectively.

CIRCUIT EVALUATION AND TEST

This section covers the setup and procedure for the CN0523 circuit

evaluation. For complete details, refer to the EVAL-CN0523-EBZ

User Guide.

EQUIPMENT NEEDED

►

CN0523 circuit evaluation board (EVAL-CN0523-EBZ)

►

Signal generator (Rohde & Schwarz

® SMA100B)

►

Signal analyzer (Keysight

® E5052B)

►

Vector network analyzer (Keysight N5242A PNA-X)

►

5 V; ≥0.5 A AC/DC power adapter with micro-USB cable

►

SMA cables

►

20 dB attenuator, which is optional for input protection of the

signal analyzer.

SETUP AND TEST

Figure 16 shows the proper port connection of the EVAL-CN0523-

EBZ to the vector network analyzer for S-Parameter and noise

figure testing.

Figure 16. S-Parameter and Noise Figure Measurement Setup

The procedure for measuring S-Parameters and noise figure are as

follows:

1. Set the desired measurement conditions of the vector network

analyzer as follows:

a. Set the frequency span from 5 GHz to 6 GHz.

b. Set the frequency step size to 10 kHz.

c. The power level must be less than or equal to -30 dBm.

2. Perform a full 2-port calibration of the vector network analyzer

using a calibration kit.

Note: The RF input of the EVAL-CN0523-EBZ can be connect-

ed directly to a test port, so only one measurement cable is

needed for the test setup.

3. Connect the EVAL-CN0523-EBZ across the test ports of the

vector network analyzer using the calibrated test setup.

4. Power up the EVAL-CN0523-EBZ using the 5 V power adapter.

5. Set the vector network analyzer to display the traces of the

individual S-Parameters and the noise figure.

6. Compare measurements to the expected values. At 5.8 GHz

center frequency, the values for input and output return losses

are approximately 11 dB and 15 dB, respectively. For the gain

and noise figure readings, values should be approximately 24

dB and 6.5 dB, respectively.

Figure 17 shows the proper port connection of the EVAL-CN0523-

EBZ to the signal analyzer and signal generator for phase noise

and SFDR testing.

Figure 17. Phase Noise, SFDR, and POUT vs. PIN Measurement Setup

The procedure for measuring phase noise, SFDR, and POUT vs. PIN

are as follows: