Open RF Prototyping

Super Heterodyne RF Front End

RF Signal Acquisition

Assembly

SuperHet top assembly

Figure 3a: Top side of assembly.

SuperHet reverse assembly

Figure 3b Reverse side of assembly.

Design Notes

Superhet down-conv

Figure 11: Superhet converter schematic.

The First LO

The first LO makes use of an HMC833 PLO module with the following hardware configuration:

  • A resistive splitter on the HMC833 RF output.

  • An LFCN-2850 2850 MHz low pass filter and HFCN-2700 2650 MHz high pass filter on the split outputs prior to the output buffer amplifiers.

  • A SKY65017 buffer amplifier after the HFCN-2700 high pass filter for the RF B output. (SKY65017 broadband gain block)

  • A SKY65014 buffer amplifier after the LFCN-2850 low pass filter for the RF A output. (SKY65014 general purpose gain block)

Table 6: First LO power output as a function of PLO buffer gain (PLO Output A)

Frequency (MHz)

Buffer gain

Power (dBm)

25

MAX

1.0

50

MAX

9.0

100

MAX

9.0

200

MAX

10.0

300

MAX

11.0

400

MAX

12.0

500

MAX

12.0

600

MAX - 3

10.0

700

MAX - 3

10.5

800

MAX - 3

11.0

900

MAX - 3

11.0

1000

MAX - 3

11.0

1100

MAX - 3

10.5

1200

MAX - 3

10.0

1300

MAX - 3

10.5

1400

MAX - 3

10.5

1500

MAX - 6

11.0

1600

MAX - 6

10.5

1700

MAX - 6

10.5

1800

MAX - 6

10.0

1900

MAX - 3

11.0

2000

MAX - 3

9.5

2100

MAX

10.5

2200

MAX

9.0

2300

MAX

8.0

2400

MAX

9.5

2500

MAX

10.5

2600

MAX

11.5

2700

MAX

11.0

2800

MAX

10.5

2900

MAX

9.5

Table 7: First LO power output as a function of PLO buffer gain (PLO Output B)

Frequency (MHz)

Buffer gain

Power (dBm)

3000

MAX - 6

1.9

3100

MAX - 6

2.0

3200

MAX - 6

1.2

3300

MAX - 3

2.6

3400

MAX - 3

2.4

3500

MAX - 3

2.2

3600

MAX - 3

2.3

3700

MAX - 3

2.8

3800

MAX - 6

2.4

3900

MAX - 9

1.8

4000

MAX - 9

1.8

4100

MAX - 9

2.4

4200

MAX - 9

2.9

4300

MAX - 9

3.3

4400

MAX - 9

3.3

4500

MAX - 9

3.8

4600

MAX - 9

4.2

4700

MAX - 9

3.0

4800

MAX - 6

2.0

4900

MAX

2.4

5000

MAX

0.4

5100

MAX

-2.3

5200

MAX

-4.4

5300

MAX

-5.5

5400

MAX

-5.0

5500

MAX

-5.3

5600

MAX

-4.7

5700

MAX

-3.6

5800

MAX

-3.2

5900

MAX

-3.0

6000

MAX

-2.6