диафрагмированные волноводные фильтры / 6ef797ec-a697-4e51-9356-08e9d150e4c1

A. 90°-bend waveguide

Fig. 1 shows the proposed terahertz 90°-bend waveguide

with EMXT structure. Periodic square-shaped rodsa×(a×h)

form this structure with the lattice constant P. The line defects

are

used to transmit

terahertz wave as waveguides

I.

INTRODUCTION

removing three rows of rods which also form a chamfered

Terahertz communication system integrates the

advantages

bend. The width of waveguide is 4P-a. The side view of this

90°-bend waveguide is shown in Fig. 1. The final optimized

of

microwave

communication

and

optical

communication,parameters are as follows: W = 1756 μm, H = 787 μm, a = 48

such as small size, high security, precise position, high speed

μm, h = 241 μm, P = 132 μm.

and large capacity for information [1]. Terahertz system has

broad application prospects in the future. As a part of terahertz

communication

system,

the

performance

of

terahertz

functional devices has an impact on the

performance

of

4P-a

terahertz system. Its development can not be ignored.

With

frequency

increasing,

terahertz

devices

have

a

minimum

size of less than 1

millimeter.

It’s

extremely

difficult to fabricate terahertz device with

conventional

technology,

considering

the

processing

error,

surface

roughness,

and

energy

loss.

Micro-Electro-Mechanical

W

Systems

(MEMS)

can

solve

thisproblem [2].

With

bulk

silicon MEMS technology, some cavities can be etched on the

(a)

silicon wafers. The surfaces of ilicons wafers are coated with

sputtering

gold. Silicon wafers

finally

are

connected

together

a

h

with gold-gold thermo-compression bonding

to

form

the

designed terahertz functional devices.

(b)

(c)

High precision and deep etching are typical advantages of

P

bulk

silicon

MEMS

technology to

fabricated

complex

H

structure like electromagnetic crystal (EMXT, also called

photonic crystals at optical frequency

)

[3].

For

the

electromagnetic band gaps of EMXTs, they can also be used

to transmit electromagnetic waves. These structures consist of

periodical metallic or dielectric cells which can

easily

form

(d)

passive terahertz devices, such as waveguides, filters and

antennas. The

EMXT size in

the

microwave

band

is on

the

Figure 1. Structure of proposed 90°-bend waveguide: (a) schematic diagram

order of centimeters and in the optical band is on the order of

(b) partial top view (c) partial side view (d) whole side view.

nanometers. It’s too large to integrate or too small to fabricate.

This waveguide operated from 0.365 THz to 0.578 THz

But

it’s

suitable

in

terahertz

band.

Bulk

silicon

MEMS

45.2% relative bandwidth. The cross section

technology provides such means for terahertz

circuit

and

with

corresponds to WR-1.9 standard rectangular waveguides. The

components fabrication.

S parameters of this 90°-bend waveguide is presented in Fig. 2.

D

L2

W

L1

(a)

P

a

H

filter reach up to 2 dB

and 24

dB

respectively. Good

normalized radiation patterns of

H-plane

horn

antenna at the

-20

simulated E-plane

measured E-plane

-30

simulated H-plane

measured H-plane

-90

-60

-30

0

30

60

90