LT5579 Datasheet, PDF (1/20 Pages) Linear Technology – 1.5GHz to 3.8GHz High Linearity Upconverting Mixer

FEATURES
n _{High Output IP3: +27.3dBm at 2.14GHz}
n _{Low Noise Floor: –158dBm/Hz (POUT = –5dBm)}
n _{High Conversion Gain: 2.6dB at 2.14GHz}
n _{Wide Frequency Range: 1.5GHz to 3.8GHz*}
n _{Low LO Leakage}
n _{Single-Ended RF and LO}
n _{Low LO Drive Level: –1dBm}
n _{Single 3.3V Supply}
n _{5mm × 5mm QFN24 Package}
APPLICATIONS
n _{GSM/EDGE, W-CDMA, UMTS, LTE and TD-SCDMA}
Basestations
n _{2.6GHz and 3.5GHz WiMAX Basestations}
n _{2.4GHz ISM Band Transmitters}
n _{High Performance Transmitters}
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Operation over wider frequency range is possible with reduced performance.
Consult Linear Technology for information and assistance.
LT5579
1.5GHz to 3.8GHz
High Linearity
Upconverting Mixer
DESCRIPTION
The LT^®5579 mixer is a high performance upconverting
mixer optimized for frequencies in the 1.5GHz to 3.8GHz
range. The single-ended LO input and RF output ports
simplify board layout and reduce system cost. The mixer
needs only –1dBm of LO power and the balanced design
results in low LO signal leakage to the RF output. At 2.6GHz
operation, the LT5579 provides high conversion gain of
1.3dB, high OIP3 of +26dBm and a low noise floor of
–157.5dBm/Hz at a –5dBm RF output signal level.
The LT5579 offers a high performance alternative to pas-
sive mixers. Unlike passive mixers, which have conversion
loss and require high LO drive levels, the LT5579 delivers
conversion gain at significantly lower LO input levels and
is less sensitive to LO power level variations. The lower
LO drive level requirements, combined with the excellent
LO leakage performance, translate into lower LO signal
contamination of the output signal.
TYPICAL APPLICATION
Frequency Upconversion in 2.14GHz W-CDMA Transmitter
LO INPUT
–1dBm (TYP)
LO
LT5579
BIAS
11Ω
IF
INPUT
MABAES0061
4:1
82pF
1
5
40nH
IF⁺
2
33pF
3
4
IF^–
82pF
40nH
11Ω
GND
RF
RF
1.8nH ^OUTPUT
0.45pF
V_CC
5579 TA01a
V_CC
1μF
100pF
1nF ^3.3V
Gain, NF and OIP3 vs
RF Output Frequency
30
25
T_A = 25°C
20
V_CC = 3.3V
f_IF = 240MHz
f_LO = f_RF + f_IF
15
OIP3
SSB NF
10
5
GAIN
0
1900
2000 2100 2200 2300 2400
RF FREQUENCY (MHz)
5579 TA01b
5579f
1