Chip-to-package Wireless Power Transfer and its ... · HFSS Simulaton: •The total gain of the structure is about 5dB at 1.5 GHz. D [cm] Width [mm] Spacing [mm] N turns (each arm)

Slide 1 2013 IEEE Topical Conference on Biomedical Wireless Technologies, Networks & Sensing Systems, Austin, TX

Luca Aluigi#, *, Trang T. Thai*, Manos M. Tentzeris*, Federico Alimenti# and Luca Roselli#

# DIEI, University of Perugia, Via Duranti 93, 06125 Perugia, Italy

*GEDEC, Georgia Institute of Technology, Atlanta, 30332-0250, USA

Chip-to-package Wireless Power Transfer and its Application to mm-Wave Antennas and Monolithic

Radiometric Receivers

Tuesday, January 22, 2013 – Session TU5C-4 – Sabine

http://www.radiowirelessweek.org/


Outline

• Introduction • System description

• Coupling transformer • Archidean antenna

• Simulations • EM • Transistor level

• Proof-of-concept @ 1.5 GHz • Conclusion



Introduction 1-3

Complex assembly issues are related to large arrays of radiometeric receivers

Low Frequency Instrument (LFI) within the ESA Planck mission. The LFI instrument has been developed to produce high precision maps of the microwave sky at frequencies in the range 27–77 GHz.

Array with 32 radiometeric sensors. From: V. Gorishnyak, et. al., “8 mm Passive Imaging System with 32 Sensors”, IEEE EuRAD 2004, pp. 333-336.



Introduction 2-3

In this work the solution proposed in [1] for the PCB is implemented on a LCP substrate for Ka-band (35.4 GHz)

operation.

[1] F. Alimenti, et al, "A New Contactless Assembly Method for Paper Substrate Antennas and UHF RFID Chips," IEEE MTT Trans., vol.59, no.3, pp.627-637, March 2011.

CONTACTLESS APPROACH!



Introduction 3-3

•Excellent high-frequency properties •Good dimensional stability •Low bake temperature •Low bake time



System description 1-4

• Center frequency is 35.4 GHz (Ka-Band), the low atmospheric attenuation window suitable for imaging.

• Principle of operation: magnetic coupling between the antenna and the chip, obtained by a heterogeneous transformer

• the primary and secondary windings of the transformer are fabricated on the antenna flexible substrate and Si chip respectively




• On the Si-chip (i.e. on the receiver chip) the RF pads are substituted by the secondary coil of the heterogeneous transformer. This is realized by a planar winding connected to the receiver input circuitry.

• The DC supply and the data-out are then passed through the side of the LCP substrate using wire bonds.

• Low melting temperature layers are used to stick/adhere thicker high melting temperature core layers, in order to create a homogeneous package stackup.




D

[µm] Width [µm]

Spacing [µm]

N turns Thick. [µm]

Primary 220 50 50 1 9

Secondary 160 8 2 2 3

Coupling transformer

The upper coil (primary) is built on LCP’s Metal 1 and the lower coil (secondary) is built on chip using the topmost available metal in the BiCMOS process.




Archimedean spiral antenna: • Two wire configuration • Broadside • Balanced feed • Circular polarization

Feed network based on microstrip line: high-impedance connections and open stubs (balanced structure)

D [mm]

Width [µm]

Spacing [µm]

N turns (each arm)

Thick. [µm]

3.7 215 240 1.25 9



EM Simulations

HFSS Simulaton of the heterogeneous transformer: •The MAG at 35.4 GHz is -0.66 dB •86% power transfered

HFSS Simulaton of the Archimedean antenna: •The total gain of the structure is about 5dB at 35.4 GHz



Transistor-level Simulations 1-3

LNA • 250 nm SiGe BiCMOS technology from IHP foundry • Three-stages, differential, cascode • Simultaneous noise and input power matching • Bias circuitry based on a cascode current mirror optimized to keep the

gain stable over temperature changes




DETECTOR • 250 nm SiGe BiCMOS technology from IHP foundry • Full differential architecture composed by coupled common emitter

transistors forming the detector and by a dummy detector in perfect layout symmetry

• Resistive network HBT bias • RF Signal applied differentially to the bases of Q1,2 • DC output voltage taken at the common collector point




LNA Detector, -32 dBm input power

Gain [dB]

NF [dB]

S11/S22 [dB]

PDC [mW]

Resp. [mV/W]

NEP [pW/√Hz]

PDC [mW]

40.5 4.5 -40/-44 95 96 5.1 3.75

RESULTS



Conclusion

• Chip-to-package wireless power transfer has been applied to antennas and MMICs on LCP flexible substrate.

• Millimeter-wave operation is introduced and validated with EM simulations. • The proposed approach enables a significant reduction in the manufacturing cost of

imaging sensors simplifying the production while enhancing the interconnect ruggedness for conformal geometries.

• Then a purposely designed MMIC to form the complete imaging sensor is designed and simulated in a 250 nm SiGe technology showing the readiness of the selected technology for this new approach.

• The SoC radiometer will allow the innovative integration of each sensor’s front-end with the respective antenna, constituting a single element of the array.

• Thanks to this a considerable reduction in the size, cost and power consumption of the system can be achieved.



Proof-of-concept @ 1.5 GHz

Technology adopted 1-2

Very low-cost solution: Inkjet printing + …..

SILVER-INK: σ (S/m) = 6.30×106




Technology adopted 2-2

PAPER: εr = 3.2 tanδ = 0.08 thickness = 250 µm

Very low-cost solution: Inkjet printing + paper substrate





Wireless receiver concept

• Principle of operation: magnetic coupling between the antenna and the chip, obtained by a heterogeneous transformer

• the primary and secondary windings of the transformer are fabricated on the antenna flexible substrate and Si chip respectively

• On the Si-chip (i.e. on the receiver chip) the RF pads are substituted by the secondary coil of the heterogeneous transformer. This is realized by a planar winding connected to the receiver input circuitry.

• The DC supply and the data-out are then passed through the side of the substrate using wire bonds.





Flex antenna to SoC transceiver assembly: The heterogeneous transformer for magnetic coupling is formed between a coil on Top Metal (Si) and another coil on Metal 0 or Metal 1. The wire bondings are only for DC or low frequency signals.





Coupling transformer

HFSS Simulaton: •The MAG at 1.5GHz is -0.52dB •89% power transfered

D [mm]

Width [mm]

Spacing [mm]

N turns

Thick. [µm]

Primary 5 1 - 1 9

Secondary 4.6 0.3 0.1 2 3





HFSS Simulaton: •The total gain of the structure is about 5dB at 1.5 GHz.

D [cm]

Width [mm]

Spacing [mm]

N turns (each arm)

Thick. [µm]

8 5 5.5 1.25 9

Archimedean spiral antenna: • Two wire configuration • Broadside • Balanced feed • Circular polarization

Feed network based on microstrip line: high-impedance connections and open stubs (balanced structure)




Results 1-2 From top to bottom: • paper superstrate • the secondary (1-turn) coil including the input lines • glue layer (in blue). A super glue layer having dielectric constant of 3.3 and loss tangent of

0.06 with the estimated thickness of 100 µm was utilized • antenna • paper substrate




Results 2-2

The measurements of the prototype give the |S11| of -12dB at 1.5GHz. The slight shift in the measurement is due to the instrument uncertainty in the glue thickness estimation.



thank you very much for the attention

Luca Roselli


http://www.hfelab.it/

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Chip-to-package Wireless Power Transfer and its ... · HFSS Simulaton: •The total gain of the structure is about 5dB at 1.5 GHz. D [cm] Width [mm] Spacing [mm] N turns (each arm)