Limitations of On-Wafer Calibration and De-Embedding Methods in the Sub-THz Range

This paper investigates frequency limitations of calibration and de-embedding techniques for S parameter measurements. First, the TRL calibration methods are analysed and the error due to the probe movement when measuring the different line lengths is quantified, next the coupling between the probe-heads and the wafer surface is investigated and finally an upper frequency validity limit for the standard Open-Short de-embedding method is given. The measured results have been confirmed thanks to the use of an electro-magnetic simulator.

Research on COB De-embedding in Scattering Parameter Measurement

The popular radio frequency(RF) chip on board(COB) test has gradually taken the place of onwafer test due to the high efficiency and high power. This paper presents the extended Open-Short-Load(OSL) that is one-port calibration method to verify the error model de-embedding in S parameter measurement. Threelevel cascade structure on COB's system error model is proposed and analyzed. Four kinds of calibration plane solutions for de-embedding are verified. At last,on-board calibration(CAL) kits solution is established to decrease the system error to the least value. The maximum error shift can be controlled less than 0.1 dB comparing with the on-wafer test results. In general,the practical application results prove that this method is reasonable and effective and easy to be mastered.

A Novel De-Embedding Technique of Packaged GaN Transistors

This paper presents a novel de-embedding technique of packaged high-powertransistors. With the proposed technique, the packaged model of the power amplifier (PA)tube can be divided into the frequency independent de-embedded intrinsic device (DID)and the frequency dependent internal parasitic network (IPN), which is of great help in reducingthe design complexity of a broadband PA. Different from the conventional techniqueof parasitic extraction, the proposed technique only requires external measurements.The frequency independent characteristic of DID is verified and the IPN is modeledand calibrated for a 50 W gallium-nitride (GaN) transistor. At last, a broadbandDoherty PA is fabricated with the de-embedding technique. According to the measured results,the PA exhibits satisfactory power and efficiency performance.

Modeling of a Schottky Diode in CMOS Process with a Flexible “Open-Through” On-Chip De-embedding Method

Modeling of Schottky diodes in the CMOS process is a key step in ultra-high frequency （UHF） ra- dio frequency identification （RFID） transponder designs. Accurate Schottky diode models need both DC and RF models. Conventional DC models of the Schottky diode fail to predict the forward leakage current, which is crucial for precise simulation results. This paper presents a Schottky diode model with an additional diode which gives the correct forward leakage current. The RF model of the Schottky diode is constructed based on the measured S-parameters. Then, an on-chip de-embedding process is needed to remove the parasitics due to the pads and interconnection lines in the S-parameter test. A flexible ＂open-through＂ on-chip de-embedding method is proposed which only requires an ＂open＂ dummy and a ＂through＂ dummy, with all the lumped and distributed parasitics equivalent to two-port networks to give sufficient high-frequency de-embedding accuracy. By the help of this de-embedding method and the new DC model, the accuracy of the established diode model could be guaranteed. The Schottky diode model is verified by comparison between measurements and simulations and successfully applied to an RFID transponder design.

New de-embedding structures for extracting the electrical parameters of a through-silicon-via pair

Two innovative de-embedding methods are proposed for extracting an electrical model for a through- silicon-via （TSV） pair consisting of a ground-signal （GS） structure. In addition, based on microwave network theory, a new solution scheme is developed for dealing with multiple solutions of the transfer matrix during the process of de-embedding. A unique solution is determined based on the amplitude and the phase characteristic of S parameters. In the first de-embedding method, a typical ＂π＂ type model of the TSV pair is developed, which illustrates the need to allow for frequency dependence in the equivalent TSV pair Spice model. This de-embedding method is shown to be effective for extracting the electrical properties of the TSVs. The feasibility of a second de-embedding method is also investigated.

On-wafer de-embedding techniques from 0.1 to 110 GHz

On-wafer S-parameter de-embedding techniques from 0.1 to 110 GHz are researched. The solving re- suits of thru-reflect-line （TRL） and line-reflect-match （LRM） de-embedding algorithms, when the input and output ports are asymmetric, are given. The de-embedding standards of TRL and LRM are designed on an InP substrate. The validity of the de-embedding results is demonstrated through two passive components, and the accuracy of TRL and LRM de-embedding techniques is compared from 0.1 to 110 GHz. By utilizing an LRM technique in 0.1- 40 GHz and a TRL technique in 75-110 GHz, the intrinsic S-parameters of active device HBT in two frequency bands are obtained, and comparisons of the extracted small-signal current gain and the unilateral power gain before and after de-embedding are presented. The whole S-parameters of actual DUT from 0.1 to 110 GHz can be obtained by interpolation.

Multifunctional AlPO_(4)reconstructed LiMn_(2)O_(4)surface for electrochemical lithium extraction from brine

LiMn_(2)O_(4)(LMO)electrochemical lithium-ion pump has gained widespread attention due to its green,high efficiency,and low energy consumption in selectively extracting lithium from brine.However,collapse of crystal structure and loss of lithium extraction capacity caused by Mn dissolution loss limits its industrialized application.Hence,a multifunctional coating was developed by depositing amorphous AlPO_(4)on the surface of LMO using sol-gel method.The characterization and electrochemical performance test provided insights into the mechanism of Li^(+)embedment and de-embedment and revealed that multifunctional AlPO_(4)can reconstruct the physical and chemical state of LMO surface to improve the interface hydrophilicity,promote the transport of Li^(+),strengthen cycle stability.Remarkably,after 20 cycles,the capacity retention rate of 0.5AP-LMO reached 93.6%with only 0.147%Mn dissolution loss.The average Li^(+)release capacity of 0.5AP-LMO//Ag system in simulated brine is 28.77 mg/(g h),which is 90.4%higher than LMO.Encouragingly,even in the more complex Zabuye real brine,0.5AP-LMO//Ag can still maintain excellent lithium extraction performance.These results indicate that the 0.5AP-LMO//Ag lithium-ion pump shows promising potential as a Li^(+)selective extraction system.

Electrical Characterization of the through Via in Package-on-Package with Interposer using Parameter Extraction Method

This paper describes a method to extract electrical parameters of the through via in Package-on-Package(PoP)with interposer.Using the de-embedding technique electrical parameters of the through via are extracted.With the extracted electrical parameters of the through via,the effects of via height,the distance between signal and GND vias,and anti-pad clearance on the electrical characteristics are discussed. parameter extraction;de-embedding; Package-on-Package(PoP)

A 500-600 MHz GaN power amplifier with RC-LC stability network

The GaAs-based TF-IPD fabrication process and equivalent lumped element circuit are utilized to re- duce the circuit size for double-section Wilkinson power divider. Ultimately the dimension of the proposed S-band power divider is reduced to 1.03 × 0.98 mm2. Its measured results show an operating fractional bandwidth of 54%, and return losses and isolation of greater than 20 dB. In addition the excess insertion loss is less than 1.1 dB. More- over the good features contain amplitude and phase equilibrium with the values of better than 0.03 dB and 1.5° separately. This miniaturized power divider could be widely used in RF/microwave circuit systems.

A simple method of measuring differentially-excited on-wafer spiral inductor-like components

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components.This method requires only two common ‘G-S-G＇ probes and an ordinary two-port VNA.Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through＇ dummy, and thus the measurements are greatly simplified.By designing the ports ‘Open＇ or ‘Shortcircuited＇ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators.Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters（S-parameters） can be constructed.Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.