A 1 V RF front-end for both HIPERLAN2 and

802.11a

A 1 V RF front-end for both HIPERLAN2 and

802.11a

T. Taris, JB. Begueret, H. Lapuyade, Y. Deval

IXL laboratory, University of Bordeaux 1, 33405 Talence, France

OUTLINEOUTLINE

• HIPERLAN2 and 802.11a requirements

• Wireless mass market design constrains

• LNA

• MIXER

• RF Front-end

• Measurement results

• Conclusions

HIPERLAN2 and 802.11a requirementsHIPERLAN2 and 802.11a requirements

LNA VGA

PBF PBF

Mixer

LO

Communication standard

HiperLAN2 and 802.11a

gain 10 dB

Noise Figure 10 dB

ICP1 -21 dBm

IIP3 -10 dBm

Frequency band 5.15-5.35 GHz

Wireless mass market constrainsWireless mass market constrains

Wireless applications + Mass market

CMOS VLSI

analog design

Low Power / Low Voltage

Power aware systems

<10 mW / ~1V

LNALNA

Gain

Input matching Low noise figure

Ftot = FLNA+(Fmixer-1)/GLNA

Maximum signal collected

Ftot = FLNA+(Fmixer-1)/GLNA

Low power

&

Low voltage

LNALNA

RF

bias

out

MLNA

Lg

Ls

Inductive Degeneration

Tuned Load

50 input matchingLow Noise Figure

)²1.(...5

21 cF

T

sgs

m LC

gZin .

Good Linearity

Reduce Miller Effect

MixerMixer

Gain

Linearity

Mixing

operation Low power

&

Low voltageVoltage dynamic range trade-off

Mixing principle brought into play

Principle efficiency

MixerMixer

VLO

VFI

VRF

Low-pass filter

behavior

High-pass filter

behavior bias

)²(2

..TGS

oxnD VV

LWCµ

I )cos()cos( tVtVVV RFRFLOLObiasGS

tVVL

WCµi LORFLORF

oxnD )cos(...

2

..

In saturation region: Assuming:

RF Front-EndRF Front-End

LNA Mixer

Mmix

MLNA

Rconv

Cd1

Cd2

RF

LO

FI

R R

Measurement resultsMeasurement results

• Inductive degeneration matching

S11 = -26 dB Isolation LO>RF = -34 dB

• Due to closeness of RF and LO port

Measurement resultsMeasurement results

0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8Supply Voltage (V)

1

2

3

4

5

6

7

8

9

10

Gain (dB)

Gain = 10 dB @ 1 V ICP1=-9 dBm & IIP3=0 dBm

• Good input matching

• Architecture well suited to low voltage

• Efficiency of resistor load

• Bypass filter behavior

-20-25 -15 -10 Pin(dBm)

-15

-10

-5

0

Pout(dBm)

0

ICP1

IIP3

-20-25 -15 -10 Pin(dBm)

-15

-10

-5

0

Pout(dBm)

0

ICP1

IIP3

Measurement resultsMeasurement results

Measurment results

Requirements

Frequency band

5.15-5.35 GHz 5.15-5.35 GHz

Supply 1 V NC

Gain 10 dB 10 dB

Noise Figure 8 dB 10 dB

Current consumption

6 mA NC

ICP1 -9 dBm -21 dBm

IIP3 0 dBm -10 dBm

Isolation LO>RF

-34 dBm > -30 dBm

ConclusionsConclusions

Fulfill successfully both HIPERLAN2 and

802.11a requirements

Operating under 1V and consuming only 6

mA, it is well suited to low power/low voltage

applications

implemented in CMOS VLSI technologie its

weak bulkiness (750µm500µm ) dedicates it to

System On a Chip (SOC) applications

PerspectivesPerspectives

Improve isolation between LO and RF port

Architecture without inductance (matching

trade-off)

Enhance the conversion gain (linearity trade-

off)