Millimeter-​Wave & THz Sen­sor Cir­cuits

One im­por­tant key ac­tiv­ity within the pro­gram RF Cir­cuits is the re­al­iza­tion of in­te­grated millimeter-​wave cir­cuits. In par­tic­u­lar, trans­mit and re­ceive cir­cuits as well as fre­quency syn­the­siz­ers with op­er­at­ing fre­quen­cies up to 720 GHz are in the focus of the re­search and de­vel­op­ment ac­tiv­i­ties, all based on the IHP in-​house SiGe BiC­MOS processes.

In the fu­ture, radar sen­sors shall en­able ro­bust and high-​resolution sys­tems as well as novel in­no­v­a­tive ap­pli­ca­tions in the area of con­tact­less sens­ing and mul­ti­di­men­sional sur­round scan­ning with a high level of minia­tur­iza­tion. In order to pro­vide trans­ceiver fron­tend cir­cuits for many ap­pli­ca­tions rang­ing from sin­gle radar sen­sors up to multiple-​input multiple-​output (MIMO) sys­tems, a plat­form with cas­cad­able radar-​ICs was  de­vel­oped. The port­fo­lio con­tains trans­ceiver ICs tar­get­ing op­er­a­tion fre­quen­cies from 60 - 256 GHz. Start­ing at fre­quen­cies of 120 GHz on-​chip an­ten­nas (typ­i­cally folded di­pole an­ten­nas) can be in­te­grated al­low­ing very com­pact and cost ef­fec­tive so­lu­tions for dis­tance and angle mea­sure­ments.

New an­tenna con­cepts with ded­i­cated ra­di­a­tion pat­terns have been de­vel­oped for on-​chip in­te­gra­tion. Spe­cial mod­u­la­tion tech­niques to­gether with the cor­re­spond­ing base­band sig­nal pro­cess­ing allow spa­tial res­o­lu­tion in mi­crom­e­ter range, which may cover new ap­pli­ca­tion fields in med­ical tech­nolo­gies or in human-​machine in­ter­ac­tion in­ter­faces.

The con­tin­u­ing tech­ni­cal ex­plo­ration of the THz regime in cir­cuit de­sign in­creas­ingly en­ables ap­pli­ca­tions in the area of spec­troscopy and sens­ing for ma­te­r­ial char­ac­ter­i­za­tion. The ac­tiv­i­ties are still fo­cused on the on-​chip in­te­gra­tion of micro-​fluidics, nearfield sen­sors and read­out elec­tron­ics aim­ing for highly com­pact and cost ef­fec­tive lab-​on-chip so­lu­tions. One on-​going ac­tiv­ity is the de­vel­op­ment of in­te­grated cir­cuits for analy­sis of the human breath by gas spec­troscopy at fre­quen­cies of 220 - 270 GHz. Re­cently, bow-​tie-antennas were in­te­grated on-​chip, which pro­vide a con­sid­er­able im­prove­ment of fo­cus­ing the beam in com­bi­na­tion with Si lenses at the back­side of the IC. The over­all sen­si­tiv­ity of the sys­tem was sig­nif­i­cantly im­proved. Cur­rently, the in­tro­duc­tion of a sec­ond band at twice the fre­quency (440 - 540 GHz) is under de­vel­op­ment, which will fur­ther in­crease the va­ri­ety of ap­pli­ca­tions.

Main tar­gets

• cir­cuits for mm-​wave wire­less com­mu­ni­ca­tion sys­tems
• cir­cuits for sens­ing sys­tems for mm-​wave to sub-​THz fre­quency range
• RF to millimeter-​wave biosen­sors
• cir­cuits for hetero-​integrated SiGe-​InP chips

Re­search top­ics

• di­elec­tric sen­sors
• Sub-​THz spec­troscopy cir­cuits
• mil­lime­ter wave radar cir­cuits

The main focus of the mm-​wave wire­less group is the de­vel­op­ment of state-​of-the-art mm-​wave to sub-​THz cir­cuits for com­mu­ni­ca­tion and sens­ing ap­pli­ca­tions. This in­cludes com­plete multi-​channel trans­ceiver chips with fea­tures such as beam-​steering and/or on-​chip in­te­grated an­ten­nas, as well as spe­cific high per­for­mance building-​blocks such as LNA, PAs, etc. or larger blocks such as fre­quency syn­the­siz­ers. The group is also in­volved in de­sign­ing cir­cuits for hetero-​integrated SiGe-​InP chips. A fur­ther cen­tral as­pect is the ex­plo­ration of the higher fre­quency ranges and their po­ten­tial ap­pli­ca­tions, like radar based high res­o­lu­tion imag­ing. In the field of sens­ing, highly in­te­grated trans­ceivers for radar sys­tems and gas spec­troscopy ap­pli­ca­tions are among our main ac­tiv­i­ties. In ad­di­tion, we are de­vel­op­ing in­te­grated biosen­sors for cy­tom­e­try ap­pli­ca­tions and tis­sue char­ac­ter­i­za­tion based on near-​field per­mit­tiv­ity sens­ing.

Re­search re­sults

• 245 GHz data trans­mis­sion
  • with ex­ter­nal lenses       
  • in­te­grated re­ceiver with on-​chip an­tenna
• 245 GHz front ends for gas spec­troscopy
  • with ex­ter­nal lenses 
  • ~1 m trans­mis­sion dis­tance
• 0.5 THz Trans­mit­ter / Re­ceiver
  • ~ -13 dBm at 490 - 500 GHz
• X-​band sen­sor ar­rays for micro-​imaging of bio-​materials
  • based on ca­pac­i­tive sen­sor
• Ka-​band biosen­sor for in­te­gra­tion in catheters in­tended for plaque char­ac­ter­i­za­tion
  • de­tec­tion of fat and cal­cium frac­tions in water and blood

In the area of nearfield sen­sors for bio­med­ical ap­pli­ca­tions a new glu­cose sen­sor was demon­strated in the lab, which shows promis­ing test re­sults com­pared to ref­er­ence mea­sure­ments. This and other so­lu­tions de­vel­oped within the project Nex­Gen have the po­ten­tial to al­le­vi­ate the lives of care-​requiring per­sons. The project re­ceived the CATRENE In­no­va­tion Award 2019 for its future-​oriented re­sults. The work will be con­tin­ued to allow an ex­ploita­tion of the re­search re­sults in a long-​term prospec­tive.