VMMK-3603 Avago Technologies, VMMK-3603 Datasheet - Page 8

• Manufacturer Part Number: VMMK-3603
• Description: 1 - 6 Ghz Positive Gain Slope Low Noise Ampli?er In Smt Package
• Manufacturer: Avago Technologies

VMMK-3603 Applications and Usage Information
Figure 12. Evaluation/Test Board (available to qualified customers upon
request)
Biasing and Operation
The VMMK-3603 is biased with a positive supply connected
to the output pin Vd through an external user supplied
bias decoupling network. Nominal current draw is 22 mA.
A typical biasing scheme is shown in Figure 12.
Input
Figure 13. Example demonstration circuit of VMMK-3603 for broadband
operation (1 GHz to 6 GHz).
Figure 14. Biasing the VMMK-3603
8
8.2 pF
820
50 Ohm line
Input
Pad
Amp
Ground
Pad
Output
Pad
50 Ohm line
0.1 F
100 pF
Vdd
10 nH
10
8.2 pF
Output
Table 3. VMMK-3603 Demo Board BOM
A layout of a typical demo board is shown in Figure 14. The
output bias decoupling network can be easily constructed
using small surface mount components. The value of the
output inductor can have a major effect on both low and
high frequency operation. The demo board uses a 10 nH
inductor that has a self resonant frequency higher than
the maximum desired frequency of operation.
If the self-resonant frequency of the inductor is too close
to the operating band, the value of the inductor will need
to be adjusted so that the self-resonant frequency is sig-
nificantly higher than the highest frequency of operation.
A 10 ohm resistor is placed in series with the inductor
to help provide greater bandwidth and to help with low
frequency stability. To help with low frequency stability an
820 ohm resistor is used to shunt the input line to ground.
8.2 pF capacitors are used as dc blocks on the RF input and
RF output lines.
Typically a passive component company like Murata does
not specify S parameters at frequencies higher than 5 or
6 GHz for larger values of inductance making it difficult
to properly simulate amplifier performance at higher fre-
quencies. It has been observed that the Murata LQW15AN
series of 0402 inductors actually works quite well above
their normally specified frequency.
The parallel combination of the 100 pF and 0.1 μF capaci-
tors provide a low impedance in the band of operation
and at lower frequencies and should be placed as close
as possible to the inductor. The low frequency bypass
provides good rejection of power supply noise and also
provides a low impedance termination for third order low
frequency mixing products that will be generated when
multiple in-band signals are injected into any amplifier.
Component
DUT
C1
C2
C5
C6
R1
R2
L1
Value
VMMK-3603
100 pF
8.2 pF
0.1 μF
100 pF
820 Ohms
10 Ohms
10 nH