Philips Semiconductors Product data
SA6011GHz low voltage LNA and mixer
2004 Dec 14
5
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
Vcc
GND
LNA IN
GND
GND
MIXER PD
GND
LO IN
LO IN
Vcc
GND
LNA OUT
GND
MIXER IN
GND
MIXER OUT
MIXER OUT
GND
GND
Vcc
LNA IN
C1
C15
L1
56nH
C2
2.7pF
100pF
C11
100pF
C12
2.2pF
LNA OUT
C10
100pF
MIXER IN
C9
4.7pF
C13
100pF
270nH
C6
8.2pF
L = 110 mils
L = 95 mils
w = 15 mils
w = 15 mils
V
CC
1µF
100pF
SA601
C4
U1
V
CC
J1
C14
100nF
J2
EXT LO
(-7dBm, 964MHz)
J5
L = 190 mils
w = 15 mils
J4
V
CC
18pF
2.2k
C8
100nF
MIXER OUT
J3
(50Ω, 83MHz)
C3
100pF
33pF
L3
L2
470nH
R2
C5
C7
L = 535 mils
w = 10 mils
L = 535 mils
w = 10 mils
*SEE MIXER POWER GAIN NOTE BELOW
*
**
**
SPIRAL INDUCTORS ON NATURAL FR-4, 62 MILS THICK
**
***
***
SEE MIXER FILTER INTERFACE NOTE BELOW
SR00060
R1
100Ω
Figure 3. Application Circuit
CIRCUIT TECHNOLOGY
LNA
Impedance Match: Intrinsic return loss at the input and output ports
is 7dB and 9dB, respectively. With no external matching, the
associated LNA gain is ≈10dB and the noise figure is ≈1.4dB.
However, the return loss can be improved at 881MHz using
suggested L/C elements (Figure 5) as the LNA is unconditionally
stable.
Noise Match: The LNA achieves 1.6dB noise figure at 881MHz
when S
11
= -10dB. Further improvements in S
11
will slightly
decrease the NF and increase S
21
.
Temperature Compensation: The LNA has a built-in temperature
compensation scheme to reduce the gain drift to 0.003dB/°C from
–40°C to +85°C.
Supply Voltage Compensation: Unique circuitry provides gain
stabilization over wide supply voltage range. The gain changes no
more than 0.5dB when V
CC
increases from 3V to 5V.
LO Drive Level: Resistor R1 can be replaced by an inductor of
4.7nH and C3 should be adjusted to achieve a good return loss at
the LO port. Under this condition, the mixer will operate with less
than -10dBm LO drive.
IP3 Performance: C9 between Pin 16 and ground can be removed
to introduce 3dB mismatch loss, while improving the IP3 to +3dBm.
The associated noise figure is 11dB.
Mixer
Input Match: The mixer is configured for maximum gain and best
noise figure. The user needs to supply L/C elements to achieve this
performance.
Power Gain: The gain can be increased by approximately 1.5dB by
placing R2 across C7, instead of C5.
Power Down: The mixer can be disabled by connecting Pin 7 to
ground. When the mixer is disabled, 3mA is saved.
Power Combining: The mixer output circuit features passive
power combining (patent pending) to optimize conversion gain and
noise figure performance without using extra DC current or
degrading the IP3. For IF frequencies significantly different than
83MHz, the component values must be altered accordingly.
Filter Interface: For system integration where a high impedance
filter of 1kΩ is to be cascaded at the mixer IF output, capacitors C5
and C6 need to be changed to 27pF and 1000pF, respectively.
