QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1233A-X
1.5GHZ TO 3.8GHZ HIGH LINEARITY UPCONVERTING MIXER
1
LT5579
DESCRIPTION
Demonstration circuit 1233A-x is a high linearity up-
converting mixer featuring the LT5579.
The LT
®
5579 is a high performance upconverting mixer
IC optimized for output frequencies in the 1.5GHz to
3.8GHz range. It features single-ended LO input and RF
output ports to simplify board layout and to reduce sys-
tem cost.
The LT5579 offers a superior alternative to passive mix-
ers. 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. Only
-1dBm of LO power is needed, and the balanced design
results in low LO signal leakage to the RF output. The
lower LO drive level requirements, combined with the
excellent LO leakage performance, translate into lower
LO signal contamination of the output signal.
The DC1233A-x series of demonstration circuits are
designed for evaluating the LT5579 IC at several com-
mon frequency ranges:
VERSION APPLICATION
IF INPUT
LO INPUT
RF OUTPUT
-A
WiMAX
456MHz
Low-side
3.6GHz
-B
WiMAX
456MHz
High-side
2.6GHz
-C
UMTS
240MHz
High-side
2.14GHz
-D
PCS
240MHz
Low-side
1.95GHz
Demonstration circuit 1233A-x can be easily optimized
for operations at other frequencies. Refer to the “Appli-
cation Note” section and the LT5579 data sheet for de-
tails.
Design files for this circuit board are available. Call
the LTC factory.
, LT, LTC, and LTM are registered trademarks of Linear Technology Corp.
All other trademarks are the property of their respective owners.
Table 1. Typical Demo Circuit Performance Summary (TA = 25°C, VCC = 3.3V, PIF
= -5dBm (-5dBm/tone for 2-tone tests,
∆∆∆∆
f = 1MHz),
PLO = -1dBm, unless otherwise noted. Low side LO for 1950MHz and 3600MHz. High side LO for 2140MHz and 2600MHz.)
PARAMETER
CONDITIONS
TYPICAL PERFORMANCE
Supply Voltage
3.3V
Supply Current
226mA
LO Input Frequency Range
1.1GHz to 4GHz
LO Input Power
-5 to +2dBm
1233A-A
1233A-B
1233A-C
1233A-D
WiMAX 3.6GHz
WiMAX 2.6GHz
UMTS
PCS
IF Input Frequency Range
12dB Return Loss, LO applied
330 to 505MHz
330 to 505MHz
174 to 263MHz
174 to 263MHz
RF Output Frequency Range
10dB Return Loss, LO applied
3170 to 4100MHz 2260 to 2780MHz 2035 to 2285MHz 1840 to 2020MHz
Conversion Gain
-0.5dB
1.3dB
2.6dB
1.9dB
Conversion Gain vs. Temperature
T
A
= -40°C to 85°C
-0.027dB/°C
-0.027dB/°C
-0.020dB/°C
-0.020dB/°C
Output 3rd Order Intercept
23.2dBm
26.2dBm
27.3dBm
28dBm
Output 2nd Order Intercept
54dBm
45dBm
42dBm
40dBm
Single Sideband Noise Figure
12dB
12dB
9.9dB
9.9dB
Output Noise Floor
P
OUT
= -5dBm
-155.5dBm/Hz
-157.5dBm/Hz
-158.1dBm/Hz
-158.1dBm/Hz
Output 1dB Compression
10.7dBm
13.7dBm
13.9dBm
13.6dBm
IF to LO Isolation
73dB
74dB
81dB
80dB
LO to IF Leakage
-22dBm
-26dBm
-28dBm
-25dBm
LO to RF Leakage
-35dBm
-36dBm
-35dBm
-34dBm
