IAM-91563-BLKG Datasheet IAM-91563-BLKG, IAM-91563-TR1G, IAM-91563-TR2G | P10-P12

Output

RFC

Input

L1 = 0

MLIN

C B A

-2

0.5

0.2

-0.2

0.2

-0.5

-1

Input

CBA

-2

0.5

0.2

-0.2

0.2

-0.5

-1

Output

ries C - shunt L network (from the 50 Ω source to Γ

) will

be used to match Γ

to 50 Ω. Addition of a 6.5 nH shunt

inductance moves the impedance trajectory from Point A

to Point B. The match to 50 Ω is completed with a 0.6 pF

series capacitance, C1, that moves the match to Point C,

the center of the Smith chart.

Application Example

The printed circuit layout in Figure 28 is a general purpose

layout that will accommodate components for using the

IAM-91563 for RF inputs from 800 MHz to 6 GHz. This lay-

out is a microstripline design (solid groundplane on the

backside of the circuit board) with 50 Ω interfaces for the

RF input, IF output, and LO input. The circuit is fabricated

on 0.031-inch thick FR-4 dielectric material. Plated through

holes (vias) are used to bring the ground to the top side of

the circuit where needed. Multiple vias are used to reduce

the inductance of the paths to ground.

Figure 28. PCB Layout.

1.9 GHz Design Example

To illustrate a design approach for using the IAM-91563, a

PCS band downconverter with an RF of 1.9 GHz and IF of

110 MHz is presented. The PCB layout above was used to

assemble the mixer and verify performance.

A schematic diagram of the 1.9 GHz circuit is shown in Fig-

ure 29.

Figure 29. Schematic of Example Application Circuit.

At the RF input port, series capacitor C1 and transmission

line MLIN form the input matching network and high pass

lter. (Note: The PCB layout above has provision for an in-

ductor, L1, in series with MLIN. Inductor L1 is not used in

this design.)

Referring to the table of Reection Coecients, the RF

input port Γ

= 0.82 ∠−37° at 1.9 GHz. This point is plot-

ted as Point A on the Smith chart in Figure 30. For reasons

previously discussed in the “RF Port” section above, a se-

Figure 30. RF Input Impedance Match.

For this example, the shunt inductor was realized with the

transmission line, MLIN in Figure 29 (Z

= 90Ω, length =

0.35 in.). A high quality capacitor should be selected for

C1 to minimize the eects of the capacitor’s parasitic in-

ductance and resistance. Series capacitor C1 also serves

to block any DC that may be present at the output of the

stage preceding the mixer.

At the IF output, the low pass lter and impedance match is

formed by shunt capacitor C2 and series inductor L2. Refer-

ring again to the table of Reection Coecients, the IF out-

put port Γ

= 0.64 ∠ -8° at 100 MHz, which is the frequency

point closest to the desired IF of 110 MHz. Γ

is plotted as

Point A in Figure 31.

Figure 31. IF Input Impedance Match.

IAM-91

MUN 1

L 1

C 1

C 7

RFC

IAM-91

Adding a shunt capacitance (C2) of 11.3 pF brings the im-

pedance to Point B. The match to Point C at the center of

the chart is completed with a series inductance (L2) of 150

nH.

Although not necessary for many applications, the match

at the LO port can be improved by the addition of series

inductor L3 with a value of approximately 8 nH. Design in-

formation (Γ

) for matching the LO port is obtained from

the table of Reection Coecients. Capacitor C7 is a DC

block for the LO port.

DC bias is applied to the IAM-91563 through the RFC at

the IF Output pin. The power supply is bypassed to ground

with capacitor C5 to keep RF, IF, and LO signals o of the

DC bias lines and to prevent gain dips or peaks in the re-

sponse of the mixer. C4 is a DC blocking capacitor for the

output.

The values of the RF bypass capacitors and DC blocking

capacitors that are not part of a impedance matching

structure (i.e., C3 - C7) should be chosen to provide a small

reactance (typically < 5 ohms) at the lowest frequency at

the port for which they are used. The reactance of the RF

choke (RFC) should be high (e.g., several hundred ohms)

at the lowest IF.

The completed 1.9 GHz mixer from the design example

above with all components and SMA connectors in place

is shown in Figure 32. Again, L1 is not used and is replaced

by a metal tab. The length of the shunt transmission line,

MLIN, is adjustable by moving the position of the short-

ing tab between the line and the ground pad. Provision is

made for an additional bypass capacitor, C6, to be added

to the bias line near the V

connection to eliminate un-

wanted RF feedback through bias lines.

When multiple bypass capacitors are used, consideration

should be given to potential resonances. It is important

to ensure that the capacitors, when combined with addi-

tional parasitic L’s and C’s on the circuit board, do not form

resonant circuits. The addition of a small value resistor in

the bias supply line between bypass capacitors will often

“de-Q” the bias circuit and eliminate resonance eects.

Table 1 summarizes the component values for the 1.9 GHz

design.

Table 1. Component Values for 1.9 GHz Downconverter.

Component Value

C1 0.5 pF

C2 9 pF

C3, C5, C7 100 pF

C4 500 pF

L1 (not used)

L2 100 nH

L3 8.2 nH

MLIN Zo=90 Ω

l = 0.41 in.

RFC 320 nH

The values shown in Table 1 may vary from those used

above to describe the basic impedance matching ap-

proach. The nal component values take into consider-

ation additional eects such as, the various line lengths

between components, parasitics in components (e.g., the

series inductance in C1), as well as other circuit parasitics.

A CAD program such as Avago Touchstone

may be used

to fully analyze and account for these circuit variables.

Figure 32. Complete 1.9 GHz Mixer.

The following performance was measured for a 1.9 GHz

circuit:

Measured results:

Conversion Gain = 9.0 dB LO-RF Isolation = 17 dB

SSB Noise Figure = 8.5 dB LO-IF Isolation = 34 dB

1dB

(output) = -8.1 dB RF-IF Isolation = 23 dB

(Input) = -7 dBm

Operating conditions:

RF Frequency = 1.89 GHz LO Drive Level = -5 dBm

LO Frequency = 1.78 GHz DC Power = 3.0V @ 9 mA

IF Frequency = 110 MHz

220 nH

100 pF

0.5 pF

100 pF

500 pF

4.7 pF

110 Ω, 3 mm

68 nH

GND

2200

MHz

2450

MHz

250

MHz

3.3 nH

50 Ω

0.026

0.079

0.018

0.039

Dimensions in inches.

220 nH

100 pF

0.9 pF

220 pF

1000 pF

15 pF

10 nH

180 nH

GND

2200

MHz

2450

MHz

250

MHz

50 Ω

Measured results:

Conversion Gain = 7.7 dB LO-RF Isolation = 16 dB

SSB Noise Figure = 11 dB LO-IF Isolation = 35 dB

1 dB Compression = -8.7 dB RF-IF Isolation = 27 dB

IP3 (Input) = -7 dBm

Operating conditions:

RF Frequency = 2.45 GHz LO Drive Level = -5 dBm

IF Frequency = 250 MHz DC Power = 3.0V @ 9 mA

LO Frequency = 2.2 GHz

Figure 34. 2.4 GHz ISM Band Mixer.

SOT-363 PCB Footprint

A recommended PCB pad layout for the miniature SOT-

363 (SC-70) package used by the IAM-91563 is shown in

Figure 35 (dimensions are in inches). This layout provides

ample allowance for package placement by automated

assembly equipment without adding parasitics that could

impair the high frequency RF performance of the IAM-

91563. The layout is shown with a nominal SOT-363 pack-

age footprint superimposed on the PCB pads.

Measured results:

Conversion Gain = 10.6 dB LO-RF Isolation = 21 dB

SSB Noise Figure = 7.1 dB LO-IF Isolation = 33 dB

1 dB Compression = -7.0 dB RF-IF Isolation = 17 dB

P3 (Input) = -7 dBm

Operating conditions:

RF Frequency = 900 MHz LO Drive Level = -5 dBm

IF Frequency = 80 MHz DC Power = 3.0V @ 9 mA

LO Frequency = 980 MHz

Figure 33. 800-900 MHz Cellular and ISM Band Mixer.

Designs for Other Frequencies

The same design methodology described above can be

applied to other wireless frequency bands. Design ex-

amples and measurement results for the 900 MHz and 2.4

GHz bands are shown in Figures 33 and 34.

Figure 35. Recommended PCB Pad Layout for Avago’s SC70 6L/SOT-363

Products.

P1-P3 P4-P6 P7-P9 P10-P12 P13-P14

IAM-91563-BLKG

Mfr. #:

Buy IAM-91563-BLKG

Manufacturer:

Broadcom / Avago

Description:

Up-Down Converters 3 SV 9 dB

Lifecycle:

New from this manufacturer.

Delivery:

DHL FedEx Ups TNT EMS

Payment:

T/T Paypal Visa MoneyGram Western Union

IAM-91563-BLKG

IAM-91563-BLKG

Products related to this Datasheet