Results

Characterization of micromachined membrane suspended antenna array at 94 GHz of the front-end for passive imaging

IMT investigated on-chip antennas supported by thin dielectric membranes as key building blocks for the 94 GHz high-sensitivity antenna front-end for passive imaging. The antennas were investigated for both high- (10 kΩcm) and low-resistivity (10 Ωcm) silicon substrates. The substrate under the active area of the antennas can be removed through deep reactive ion etching or through wet etching, in order to release the thin dielectric membrane.


(a).


(b)

Simulated results for; (a) reflection losses for high-resistivity (red, dotted line) and low-resistivity (black, slash-dotted line) silicon micromachined 2x1 antenna structures; (b) 3D radiation pattern of the micromachined 2x1 antenna structure


Fig. IMT3. 3X1 array processed through wet micromachining of silicon

An experimental setup for antenna characterization was developed around the Anritsu 37397D VNA with OML extension modules up to 110 GHz


Measurement setup for W band micromachined antenna experiments


(a).


(b)

 

Measured (black, solid line) vs. simulated (red, dotted line) reflection losses for high-resistivity: (a) 2x1 array; (b) 3x1 array


(a)


(b)

 

 (a) measurement setup and (b) radiation results for reflector backed high-resistivity 2x1 array

Design of 140GHz antennas

IMT investigated 140 GHz double folded slot antennas processed on thin dielectric membranes released through micromachining of a silicon substrate


(a)


(b)


(c)

140 GHz antenna structure: (a) 3D view of the EM model; (b) simulation results for HR (green, solid line) and LR (blue, dotted line) reflection losses; (c) simulation results for HR (green, solid line) and LR (blue, dotted line) gain as a function of frequency

Results 2012

Growth of CNTs by PECVD. SEM images are presented.
SEM images of CNT area

Design and simulation of micromachined membrane suspended antenna array at 94 GHz of the front-end for passive imaging

a                                                              b


                            c


The 3D electromagnetic model in CST microwave Studio: (a) front view of the 2x1 array; (b) front view of the 3x1 array; (c) transversal section of the 2x1 array;

The electromagnetic simulations showed good results with the 2x1 array having simulated reflection losses lower than –10 dB between 84.5 – 106.7 GHz, while the 3x1 array shows reflection losses lower than – 8 dB between 73 – 100 GHz


 

                                          a                                                               b
Simulated reflection losses for: (a) the 2x1 array; (b) the 3x1


                                       a                                   


                                       b                                   

                             3D radiation pattern for: (a) the 2x1 array; (b) the 3x1

Electromagnetic modelling of the MEMS switch for the GaAs technology


The layout of the SW model developed in IE3D

 

The 3D view of the IE3D EM model with thick metal


 

The 3D view of the IE3D EM model with thin metal in the UP and DOWN positions


Comparison between simulated S parameters  obtained using IE3D models for thin and thick

 

Design of the Dicke switch for 94 GHz high-sensitivity (switched low-noise) antenna front-end for passive imaging realized using GaAs and SiGe RF-MEMS


The layout of the Dicke SW in GaAs technology (mask set)


Layout 2D pentru modelul electromagnetic IE3D al comutatorului Dicke


 


Simulated and measured results for the Dicke SW in GaAs technology for the "transmission" state (insertion losses)


Simulated and measured results for the Dicke SW in GaAs technology for the "isolation" state