AT-41532-BLK 데이터 시트보기 (PDF) - HP => Agilent Technologies

부품명

상세내역

제조사

AT-41532-BLK

General Purpose, Low Current NPN Silicon Bipolar Transistor

HP => Agilent Technologies 

12

Measured input and output return

loss is shown in Figure 21. The

input return loss is 10 dB at

850 MHz and can be improved

with slight tuning at C2. Output

return loss was measured at

almost 10 dB at 850 MHz.

16

14

12

10

8

6

500 600 700 800 900

FREQUENCY (MHz)

Figure 19. Gain vs Frequency.

1000

1.6

1.5

1.4

1.3

1.2

1.1

1

500 600 700 800 900 1000

FREQUENCY (MHz)

Figure 20. Noise Figure vs Frequency.

0

-2

-4

-6

-8

-10

-12

-14

500

Input

Output

600 700 800 900

FREQUENCY (MHz)

1000

Figure 21. Input/Output Return Loss.

There is considerable tuning

interaction between input and

output matching networks in any

single stage amplifier. Having a

somewhat better input return loss

coincident with low noise figure

may necessitate a compromise in

output return loss.

Output intercept point, IP3, was

measured at 850 MHz to be

+12 dBm. Removing the 1.1 KΩ

resistor at R6 increases IP3 to

+13.6 dBm. Resistor R6 was

originally added to enhance

stability; caution is urged when

removing this resistor or increas-

ing its value without careful

analysis. Another alternative to

the shunt resistor R6 would be to

incorporate a resistor in series

with the transistor collector lead.

This resistor would be in the 10 to

27 Ω range and has similar effects

on circuit stability. A third

alternative is to re-optimize the

output match for power as

opposed to matching for lowest

output VSWR. This may make the

output return loss less than 10 dB

but it would enhance power

output.

Modifications to Original

Demo Board

The original demo board dated

01/98 requires some modification

to work as described in this

application note. The modifica-

tion is to add resistor R6 in series

with the collector lead. This is

accomplished by cutting the etch

at the output of Q1 such that

resistor R6 can be placed on the

circuit board as shown in

Figure 17. Inductor L3 will then

have be placed at a 90 degree

angle with respect to its original

intended location. L3 is then

connected to the junction of R6

and L4 with a small piece of wire

or etch.

Using the AT-41532 at Other

Frequencies

The demo board and design

techniques presented here can be

used to build low noise amplifiers

for other frequencies in the VHF

through 1.9 GHz frequency range.

Share Link: