CN204832482U - At piece S parameter co -planar waveguide TRL calibration piece - Google Patents

Abstract

The utility model discloses an at piece S parameter co -planar waveguide TRL calibration piece relates to the terahertz now at piece S parameter testing technical field. The calibration piece is including the substrate layer, the preparation material of substrate layer is the same with the substrate material of measured piece, the upper surface of substrate layer is equipped with direct standard component, reflection standard component and transmission line standard component, the lower surface of substrate covers there is the metal level, the ground wire of direct standard component, reflection standard component and transmission line standard component is connected with the metal level in the through -hole of substrate layer through running through respectively, the probe terminal point department of the ground wire of direct standard component, reflection standard component and transmission line standard component is equipped with the mark mark. A calibration calibration accuracy is higher, operates simplyr to the error of having avoided going the embedding to bring, sign device property that can be more accurate.

Description

At sheet S parameter co-planar waveguide TRL calibrating device

Technical field

The utility model relates to Terahertz in sheet S parameter proving installation technical field, particularly relates to a kind of at sheet S parameter co-planar waveguide TRL calibrating device.

Background technology

THz wave is also called submillimeter wave, and its strict difinition refers to the frequency separation of 300GHz-3000GHz, and wavelength coverage is 1mm-0.1 μm.THz wave, compared with microwave and millimeter wave, has the advantages such as frequency is high, security good, see-through capabilities is strong, has very tempting application prospect in fields such as imaging, radar, communication, frequency spectrum, radio astronomies.

The frequency of operation of current InPPHEMT has reached Terahertz frequency range.Along with frequency of operation is more and more higher, on the sheet being directed to the wafer scale device of InPPHEMT, small-signal scattering parameter (S parameter) test proposes more and more higher requirement.The small signal S-parameters On-wafer measurement of Terahertz frequency range is analysis device frequency characteristic and carries out the basis of organs weight, and device model is the necessary requirement of carrying out Terahertz monolithic design, therefore accurately test component is extremely important in the S parameter of Terahertz frequency range.But small signal S-parameters detection calibration part commercial is at present mainly based on millimeter wave frequency band, and calibrating device and the different calibration errors brought of the backing material of measured piece (DUT), all cannot reach the test request of Terahertz frequency range.Therefore be necessary to develop based on InPPHEMT device the InP substrate calibrating device being applicable to Terahertz small signal S-parameters On-wafer measurement.

Utility model content

Technical problem to be solved in the utility model is to provide a kind of at sheet S parameter co-planar waveguide TRL calibrating device, and it is high that described calibrating device has calibration accuracy, feature simple to operate.

For solving the problems of the technologies described above, technical solution adopted in the utility model is: a kind of at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: comprise substrate layer, the making material of described substrate layer is identical with the backing material of measured piece, the upper surface of described substrate layer is provided with straight-through standard component Thru, reflectance standards Reflect and transmission line standard component Line, the lower surface of described substrate is coated with metal level, described straight-through standard component Thru, reflectance standards Reflect is connected with metal level respectively by the through hole through substrate layer with the ground wire of transmission line standard component Line, described straight-through standard component Thru, the probe destination county of the ground wire of reflectance standards Reflect and transmission line standard component Line is provided with mark mark.

Further technical scheme is: described upside or downside mark mark being positioned to described ground wire.

Further technical scheme is: the making material of described substrate is InP.

Further technical scheme is: the relative dielectric constant of described substrate layer is 12.5, and thickness is 50 μm.

Further technical scheme is: the characteristic impedance of described straight-through standard component Thru and transmission line standard component Line is 50 Ω, and calibration frequency scope during calibration is 220GHz-325GHz.

Further technical scheme is: the thickness of described metal level is 2um, and making material is gold.

Further technical scheme is: the length of described straight-through standard component Thru is 120 μm, and the length value leading directly to standard component Thru during calibration is defined as 0 μm; Described reflectance standards Reflect adopts open-circuit structure, and during calibration, delay compensation is defined as 0ps.

Further technical scheme is: described transmission line standard component Line has 3, length is respectively 210 μm, 240 μm and 270 μm, during calibration, the relatively straight-through length of standard component Thru to each transmission line standard component Line defines, and definition value is respectively 90 μm, 120 μm and 150 μm.

Further technical scheme is: the width of described ground wire is 100 μm, and the wide of described through hole is 25 μm, and length is 60 μm.

Further technical scheme is: described to mark mark length and wide be 4 μm.

The beneficial effect adopting technique scheme to produce is: the backing material of calibrating device is identical with the backing material of measured piece DUT, and calibration accuracy is higher; The version of calibrating device is identical with measured piece DUT, and the reference planes after calibration can be made to be positioned at the intrinsic region port of device, and operation is simpler, and avoids the error that De-embedding brings; Mark mark be ensure that the electrical length of coplanar waveguide transmission line is consistent with definition value after each pressure probe, and can not interference be produced; By calibration, directly test obtains the S parameter of device at 220GHz-325GHz, avoids low frequency S parameter and to extrapolate the error brought, can characterizing device characteristic more accurately.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model;

The initial position structural representation of probe when Fig. 2 is test;

The final position structural representation of probe when Fig. 3 is test;

Fig. 4 is the structural representation of InPPHEMT measured piece and calibrating device;

Fig. 5 is bandpass filter checking part schematic diagram;

Wherein: 1, substrate layer 2, straight-through standard component Thru3, reflectance standards Reflect4, transmission line standard component Line5, metal level 6, ground wire 7, through hole 8, to mark mark 9, probe 10, measured piece.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only a part of embodiment of the present utility model, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

Set forth a lot of detail in the following description so that fully understand the utility model, but the utility model can also adopt other to be different from alternate manner described here to implement, those skilled in the art can when doing similar popularization without prejudice to when the utility model intension, and therefore the utility model is by the restriction of following public specific embodiment.

As shown in Figure 1, the utility model discloses a kind of at sheet S parameter co-planar waveguide TRL calibrating device, the making material of substrate is identical with the backing material of measured piece DUT, and the geometry of corresponding probe terminal is consistent with measured piece DUT.Comprise InP substrate layer 2, the making material of preferred described substrate layer is InP, the upper surface of described substrate layer 2 is provided with straight-through standard component Thru2, reflectance standards Reflect3 and transmission line standard component Line4, its lower surface is connected with metal level 5, and described straight-through standard component Thru2, reflectance standards Reflect3 are connected with described metal level 5 respectively by the through hole 7 running through substrate layer 2 with the ground wire 6 of transmission line standard component Line4; The characteristic impedance of described straight-through standard component Thru2 and transmission line standard component Line4 is 50 Ω, and calibration frequency scope during calibration is 220GHz-325GHz;

The relative dielectric constant of described substrate layer 2 is 12.5, and thickness is 50 μm, and the thickness of described metal level 5 is 2um, and its material is gold; The length of described straight-through standard component Thru2 is 120 μm, and the length value leading directly to standard component Thru2 during calibration is defined as 0 μm; Described reflectance standards Reflect3 adopts open circuit to realize, and during calibration, delay compensation is defined as 0ps; Described transmission line standard component Line4 has 3, is respectively 210 μm, 240 μm and 270 μm, and during calibration, the relatively straight-through length of standard component Thru2 to each transmission line standard component Line defines, and definition value is respectively 90 μm, 120 μm and 150 μm; The probe destination county of described straight-through standard component Thru2, reflectance standards Reflect3 and transmission line standard component Line4 is provided with mark mark 8, is describedly of a size of 4 μm × 4 μm to mark mark 8.

As Figure 2-3, the side that the utility model leads directly to the ground wire of standard component Thru2, reflectance standards Reflect3 and transmission line standard component Line4 is provided with mark mark, ensure that each terminal of probe is at same position, when making calibration, effective electrical length is consistent with definition value, owing to being made in the side of ground wire away from center conductor to mark mark, therefore interference can not be produced.

For InPPHEMT device detection, as shown in Figure 4, be connected with vector network analyzer to make measured piece DUT, need to make probe PAD in the intrinsic region port design of InPPHEMT device, and between probe terminal and device intrinsic, there is the band line that length is 60 μm, therefore need to make TRL calibrating device, the design of probe terminal is consistent with measured piece DUT, distribution parameter when making calibration and test near probe terminal is identical, utilizes zero method led directly to reference to plane calibration to intrinsic region port when TRL calibrates.

The making of co-planar waveguide TRL calibrating device will ensure microstrip line characteristic impedance value Z ₀equal resistance value 50 Ω of system, and manufacture craft is identical with InPPHEMT device making technics, the specific inductive capacity of InP substrate is 12.5, thickness is 50 μm, the thickness of metallic conductor is 2 μm, utilize 3 D electromagnetic field simulation software, can determine that characteristic impedance be the width of the center conductor of coplanar waveguide transmission line under 50 Ω is 26 μm, the spacing of center conductor and ground wire is 24 μm.

The effective dielectric constant ε of known delay line _effwith light speed c in a vacuum, the velocity of propagation v of known electromagnetic wave in microstrip line _p:

$v_p=\frac{c}{\sqrt{{\mathrm{\ϵ}}_{eff}}}$

In formula, ε _efffor effective dielectric constant, it considers an electromagnetic wave part and propagates in media as well, this fact that a part is propagated in atmosphere, ε _effcan calculate with simulation software.Length is the transmission line relative delay t of l _delaycan be obtained by following formulae discovery:

$t_{delay}=\frac{l}{v_p}=\frac{l\sqrt{{\mathrm{\ϵ}}_{eff}}}{c}$

Frequency is that the electromagnetic signal of f is transmitted in this coplanar waveguide transmission line, after transmission line, and microwave signal relative phase changes delta P _degreeobtain by following formulae discovery:

${\mathrm{\ΔP}}_{\mathrm{deg}ree}=f\·t_{delay}\·360=\frac{360lf\sqrt{{\mathrm{\ϵ}}_{eff}}}{c}$

Design and after making co-planar waveguide microstrip transmission line, phase place with each transmission line straight-through by vector network analyzer test, realizes calibration.

The definition of TRL calibrating device, use and verify:

In vector network analyzer testing software, define zero straight-through TRL calibrating device, the length of transmission line and frequency range are inputed in software, ensure that transmission line can cover the frequency range of 220GHz-325GHz.

The position of probe terminal and effective electrical length of coplanar waveguide transmission line also exist and are closely connected, and probe, in the distance of metal surface sliding distance, will cause the electrical length of coplanar waveguide transmission line less than normal or bigger than normal compared with definition value, give during calibration and bring error.In order to ensure to press the electrical length of coplanar waveguide transmission line after probe consistent with definition value at every turn, devise in the side of ground wire probe terminal to mark mark, as Figure 2-3.

Assessing to calibrate effect to zero straight-through TRL, while making calibrating device, having made bandpass filter as passive checking part, be used for verifying calibration effect, as shown in Figure 5, by checking, test result and design result are coincide, and the calibration effect reaching expection is described.

Claims (10)

1. one kind at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: comprise substrate layer (1), the making material of described substrate layer (1) is identical with the backing material of measured piece, the upper surface of described substrate layer (1) is provided with straight-through standard component Thru(2), reflectance standards Reflect(3) and transmission line standard component Line(4), the lower surface of described substrate (1) is coated with metal level (5), described straight-through standard component Thru(2), reflectance standards Reflect(3) with transmission line standard component Line(4) ground wire (6) be connected with metal level (5) respectively by the through hole (7) through substrate layer (1), described straight-through standard component Thru(2), reflectance standards Reflect(3) and transmission line standard component Line(4) the probe destination county of ground wire (6) be provided with mark mark (8).

2. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: described upside or downside mark mark (8) being positioned to described ground wire (6).

3. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: the making material of described substrate (1) is InP.

4. according to claim 3 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: the relative dielectric constant of described substrate layer (1) is 12.5, and thickness is 50 μm.

5. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, to it is characterized in that: described straight-through standard component Thru(2) and transmission line standard component Line(4) characteristic impedance be 50 Ω.

6. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: the thickness of described metal level (5) is 2um, making material is gold.

7. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, to it is characterized in that: described straight-through standard component Thru(2) length be 120 μm; Described reflectance standards Reflect(3) adopt open-circuit structure.

8. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: described transmission line standard component Line(4) there are 3, length is respectively 210 μm, 240 μm and 270 μm.

9. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: the width of described ground wire (6) is 100 μm, the wide of described through hole is 25 μm, and length is 60 μm.

10. according to claim 1 at sheet S parameter co-planar waveguide TRL calibrating device, it is characterized in that: described to mark mark (8) length and wide be 4 μm.