All Stories

  1. Area Tracing: An Efficient Modeling Framework of Regional Channel Impulse Response in Multipath Fading Environments

    Article • IEEE Transactions on Antennas and Propagation, January 2026, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  2. Simulation Analysis of a PLPDA mounted on a UAV using Hybrid Solver Methods

    Article • IEEE Transactions on Antennas and Propagation, January 2026, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  3. Ultra-Compact Camera-Integrated Deep-Implanted Two-Port MIMO Antenna for High-Data-Rate Wireless Capsule Endoscopy

    Article • IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology, September 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  4. A Physics-Informed Deep Ray Tracing Network for Regional Channel Impulse Response Estimation

    Article • IEEE Transactions on Wireless Communications, July 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  5. An Improved Method for Quiet Zone Evaluation Using Novel Ultrawideband Dual-Polarized Antenna

    Article • IEEE Transactions on Antennas and Propagation, April 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  6. Enhancing Aperture Efficiency of Single Parabolic Cylindrical Compact Range Based on a Linear Array Excitation Method

    Article • IEEE Transactions on Antennas and Propagation, April 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  7. Guest Editorial Measurement Technologies for Emerging 5G and Beyond Channel Characterization and Antenna Systems

    Article • IEEE Transactions on Antennas and Propagation, April 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  8. Semantic Segmentation of Multipath Fading Channel-Based Regional Map

    Article • IEEE Antennas and Wireless Propagation Letters, February 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  9. New and Emerging Directions in the Fields of Antennas and Propagation

    Article • IEEE Transactions on Antennas and Propagation, January 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh, Dr. Sima Noghanian

  10. The Ray Inversion Method to Obtain Regional Multipath Channels From Finite Impulse Responses

    Article • IEEE Antennas and Wireless Propagation Letters, January 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  11. Low-Side Lobes 3D Printed Slotted Waveguide Antenna Array for Millimeter-Wave Communication Systems

    Article • IEEE Access, January 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  12. Test Zone Characterization in RTS-Based MIMO Measurement Systems

    Article • IEEE Transactions on Instrumentation and Measurement, January 2025, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  13. A Review of Unmanned Aerial Vehicle Based Antenna and Propagation Measurements

    Article • Sensors, November 2024, MDPI AG

    Dr Tian Hong Loh

  14. A Novel Near-Field Calibration Method for Linear Array Based on Plane Wave Expansion

    Article • IEEE Transactions on Antennas and Propagation, November 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  15. Design of a Novel SiP Integrated RF Front-End Module Based on SOI Switch and SAW Filter

    Article • Sensors, October 2024, MDPI AG

    Dr Tian Hong Loh

  16. 3-D-Printed Spiral Inverted Ridge Circularly Polarized Horn Antenna With One Octave Bandwidth

    Article • IEEE Antennas and Wireless Propagation Letters, October 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  17. Area Restoration of Channel Impulse Response With Time Decomposition Based Super-Resolution Method

    Article • IEEE Transactions on Wireless Communications, August 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  18. Multiprobe-Enabled Over-the-Air Calibration of Millimeter-Wave Antenna Arrays: Concepts and experimental validations

    Article • IEEE Antennas and Propagation Magazine, August 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  19. Determining the Minimum Number of Plane Wave Generator Radiating Elements Based on SVD of the Transfer Matrix

    Article • IEEE Antennas and Wireless Propagation Letters, May 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  20. Physics-Informed Machine Learning Modelling of RF-EMF Exposure in Massive MIMO Systems

    Article • IEEE Access, January 2024, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  21. Antenna Measurement Challenges and Opportunities

    Article • Reviews of Electromagnetics, December 2023, European Association on Antennas and Propagation

    Dr Tian Hong Loh

  22. Near-Field Uniform Linear Array Calibration Based on the Extrapolation of Measured Complex Signals

    Article • IEEE Transactions on Antennas and Propagation, October 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  23. Statistical Analysis for Shielding Effectiveness Measurement of Materials Using Reverberation Chambers

    Article • IEEE Transactions on Electromagnetic Compatibility, February 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  24. A New Evaluation Framework for the Performance of Spatial Correlation in MIMO OTA Testing

    Article • IEEE Transactions on Wireless Communications, January 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  25. A Novel Gain Reference Dipole Antenna for Accurate Calibration of Over-the-Air Measurement Systems

    Article • IEEE Transactions on Instrumentation and Measurement, January 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  26. A MIMO Antenna with High Gain and Enhanced Isolation for WLAN Applications

    Article • Applied Sciences, February 2022, MDPI AG

    Dr Tian Hong Loh

  27. Minimized Triple-Band Eight-Element Antenna Array for 5G Metal-frame Smartphone Applications

    Article • Micromachines, January 2022, MDPI AG

    Dr Tian Hong Loh

  28. A Low-Cost and Efficient Single Probe Based MIMO OTA Measurement Method

    Article • IEEE Transactions on Instrumentation and Measurement, January 2022, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  29. An Empirical Study of the Stochastic Nature of Electromagnetic Field Exposure in Massive MIMO Systems

    Article • IEEE Access, January 2022, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  30. Design and Optimization of Compact Printed Log-Periodic Dipole Array Antennas with Extended Low-Frequency Response

    Article • Electronics, August 2021, MDPI AG

    Dr Tian Hong Loh

  31. Optimization of Log-Periodic TV Reception Antenna with UHF Mobile Communications Band Rejection

    Article • Electronics, November 2020, MDPI AG

    Dr Tian Hong Loh

  32. Circular Polarized 3-D-Printed Dielectric Loaded Antenna Using Inset Waveguide-to-Dielectric Transition for 5G Millimeter-Wave Application

    Article • IEEE Antennas and Wireless Propagation Letters, November 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  33. Strong, omnidirectional radar backscatter from subwavelength, 3D printed metacubes

    Article • IET Microwaves Antennas & Propagation, August 2020, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  34. Hybrid Beamforming With Switches and Phase Shifters Over Frequency-Selective Channels

    Article • IEEE Wireless Communications Letters, August 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  35. A printed LPDA antenna with improved low frequency response

    Article • August 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  36. Virtual Sensing Directional Hub MAC (VSDH-MAC) Protocol with Power Control

    Article • Electronics, July 2020, MDPI AG

    Dr Tian Hong Loh

  37. Empty Substrate-Integrated Waveguide-Fed Patch Antenna Array for 5G Millimeter-Wave Communication Systems

    Article • IEEE Antennas and Wireless Propagation Letters, May 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  38. An Assessment of the Radio Frequency Electromagnetic Field Exposure from A Massive MIMO 5G Testbed

    Article • March 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  39. Developing the First mmWave Fully-Connected Hybrid Beamformer With a Large Antenna Array

    Article • IEEE Access, January 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  40. A Closed-Form Formula of Radiation and Total Efficiency for Lossy Multiport Antennas

    Article • IEEE Antennas and Wireless Propagation Letters, December 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  41. Approximate Analytical Equations for the Stirrer Angular Correlation in a Reverberation Chamber

    Article • IEEE Transactions on Electromagnetic Compatibility, December 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  42. Guest Editorial: Metrology for 5G Technologies

    Article • IET Microwaves Antennas & Propagation, December 2019, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  43. A Wideband Spiral UHF Coupler With Tuning Nodules for Partial Discharge Detection

    Article • IEEE Transactions on Power Delivery, August 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  44. Experimental Investigation of Empty Substrate Integrated Waveguide-Fed MMW Patch Antenna for 5G Applications

    Article • August 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  45. A Compact Minimally Invasive Antenna for OTA Testing

    Article • IEEE Antennas and Wireless Propagation Letters, July 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  46. Empty Substrate Integrated Waveguide Planar Slot Antenna Array for 5G Wireless Systems

    Article • July 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  47. A novel design of a 10-dipole log-periodic antenna with LTE-800 and GSM-900 band rejection

    Article • May 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  48. Accurate antenna gain estimation using the two-antenna method

    Article • January 2019, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  49. Characterisation of Doppler shift in Millimetre Wave Vehicular Channel

    Article • January 2019, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  50. The Noise Level of Total Scattering Cross Section Measurement in a Reverberation Chamber

    Article • IEEE Antennas and Wireless Propagation Letters, October 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  51. Understanding the Temporal Fading in Wireless Industrial Networks: Measurements and Analyses

    Article • October 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  52. An investigation of millimeter wave reflectarrays for small satellite platforms

    Article • Acta Astronautica, October 2018, Elsevier

    Dr Tian Hong Loh

  53. Empty Substrate Integrated Waveguide Slot Antenna Array for 5G Applications

    Article • August 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  54. An Evaluation of Distortion and Interference Sources Originating Within a Millimeter-Wave MIMO Testbed for 5G Communications

    Article • May 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  55. Millimeter-Wave Over-the-Air Signal-to-Interference-plus-Noise-Ratio Measurements Using a MIMO Testbed

    Article • May 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  56. A Ka‐band antenna based on an enhanced Franklin model for 5G cellular networks

    Article • Microwave and Optical Technology Letters, April 2018, Wiley

    Dr Tian Hong Loh

  57. A rigorous link performance and measurement uncertainty assessment for MIMO OTA characterisation

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  58. Efficient Uncertainty Evaluation of Vector Network Analyser Measurements Using Two-Tier Bayesian Analysis and Monte Carlo Method

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  59. Empty Substrate Integrated Waveguide-Fed MMW Aperture-Coupled Patch Antenna for 5G Applications

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  60. Prediction of SINR using BER and EVM for Massive MIMO Applications

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  61. Single Layer PCB Broadband Circular Polarisation Millimetre Wave Massive MIMO Array

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  62. Investigation of bandpass filters in the time domain signal analysis of reverberation chamber

    Article • August 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  63. Routing and link performance assessment of a wireless sensor network in a reverberation chamber with different absorber loading conditions

    Article • August 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  64. A millimeter wave MIMO testbed for 5G communications

    Article • June 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  65. Evaluation of Chamber Effects on Antenna Efficiency Measurements Using Non-reference Antenna Methods in Two Reverberation Chambers

    Article • IET Microwaves Antennas & Propagation, May 2017, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  66. The residual errors of multiport VNA measurements due to non-ideal TRM calibration

    Article • May 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  67. An efficient algorithm for electrically large reflectarray antenna design automation

    Article • May 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  68. How coarse is too coarse in electrically large reflectarray smart antennas?

    Article • May 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  69. An electronically steerable parasitic array radiator antenna with adaptive beamforming ability

    Article • May 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  70. The effect of receiving antenna orientation and polarization on measurements of antenna efficiency in a reverberation chamber

    Article • March 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  71. A high gain steerable millimeter-wave antenna array for 5G smartphone applications

    Article • March 2017, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  72. Millimetre wave reflectarray antenna unit cell measurements

    Article • January 2017, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  73. Role of Surface Waves in the Reflection Properties of a Millimetre Wave Reflectarray Unit Cell

    Article • January 2017, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  74. Measurement of absorption cross section of a lossy object in reverberation chamber without the need for calibration

    Article • November 2016, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  75. A Simple Recursively Computable Lower Bound on the Noncoherent Capacity of Highly Underspread Fading Channels

    Article • IEEE Transactions on Wireless Communications, June 2016, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  76. A software-defined-radio platform for multiple-input-multiple-output over-the-air measurement

    Article • April 2016, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  77. Compact Smart Antenna With Electronic Beam-Switching and Reconfigurable Polarizations

    Article • IEEE Transactions on Antennas and Propagation, December 2015, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Qi Luo, Dr Tian Hong Loh

  78. A comparison of antenna efficiency measurements performed in two reverberation chambers using non-reference antenna methods

    Article • November 2015, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  79. A novel tunable high impedance surface electromagnetic band gap metamaterials for RF and microwave applications

    Article • July 2015, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  80. A comparison of MIMO antenna efficiency measurements performed in Anechoic Chamber and Reverberation Chamber

    Article • May 2015, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  81. Assessment of the adaptive routing performance of a Wireless Sensor Network using smart antennas

    Article • IET Wireless Sensor Systems, December 2014, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  82. Assessment of a low-profile planar antenna for a wireless sensor network monitoring the local water distribution network

    Article • IET Wireless Sensor Systems, December 2014, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  83. Experimental evaluation of wearable antenna efficiency for applications in body-centric wireless networks

    Article • December 2014, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  84. On the Analogy Between Vehicle and Vehicle-Like Cavities With Reverberation Chambers

    Article • IEEE Transactions on Antennas and Propagation, December 2014, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  85. Radiation Pattern Measurement of a Low-Profile Wearable Antenna Using an Optical Fibre and a Solid Anthropomorphic Phantom

    Article • Electronics, August 2014, MDPI AG

    Dr Tian Hong Loh

  86. Characterizing the Spectral Properties and Time Variation of the In-Vehicle Wireless Communication Channel

    Article • IEEE Transactions on Communications, July 2014, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  87. An Impulse Response Model and $Q$ -Factor Estimation for Vehicle Cavities

    Article • IEEE Transactions on Vehicular Technology, November 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  88. Non-invasive measurement of electrically small ultra-wideband and smart antennas

    Article • November 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  89. A Cost-Effective Direct Magnitude Measurement Methodology for Smart Antennas

    Article • IEEE Transactions on Antennas and Propagation, April 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  90. Small Director Array for Low-Profile Smart Antennas Achieving Higher Gain

    Article • IEEE Transactions on Antennas and Propagation, January 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  91. Compact MIMO Antenna With Frequency Reconfigurability and Adaptive Radiation Patterns

    Article • IEEE Antennas and Wireless Propagation Letters, January 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  92. Low-cost beam-switching circularly-polarised antenna using tunable high impedance surface

    Article • November 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  93. Radiation pattern characterisation of embedded radios emitting modulated signals

    Article • May 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  94. Electrically Small and Low Cost Smart Antenna for Wireless Communication

    Article • IEEE Transactions on Antennas and Propagation, March 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  95. Low cost beam switchable reflectarray antenna

    Article • March 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  96. Phantoms for antenna measurements at 2.4 GHz

    Article • March 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  97. A Study on Frequency Diversity for Intra-Vehicular Wireless Sensor Networks (WSNs)

    Article • September 2011, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  98. Effects of antenna mount on a spherical scanning measurement of the radiation efficiency of a wire antenna

    Article • September 2011, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  99. Compact Dual-Band Antenna With Electronic Beam-Steering and Beamforming Capability

    Article • IEEE Antennas and Wireless Propagation Letters, January 2011, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  100. Measurement of electrically small antennas via optical fibre

    Article • November 2009, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  101. Compact-size Electronically Steerable Parasitic Array Radiator antenna

    Article • November 2009, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  102. Small smart antenna composed of reconfigurable inverted F-type antenna

    Article • January 2009, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  103. New facility for minimally invasive measurements of electrically small antennas

    Article • March 2008, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  104. Indoor radiowave propagation for UWB wireless communication systems

    Article • January 2008, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  105. Comparison of electric field strength at VHF frequencies generated by dipoles and TEM cells

    Article • September 2007, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  106. Small antenna pattern testing - the antenna-to-range interface

    Article • January 2007, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh

  107. A Method to Minimize Emission Measurement Uncertainty of Electrically Large EUTs in GTEM Cells and FARs Above 1 GHz

    Article • IEEE Transactions on Electromagnetic Compatibility, November 2006, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  108. Antenna height scan for minimizing EUT emission measurement uncertainty in fully anechoic chambers above 1 GHz

    Article • January 2006, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  109. Implementation of an Exact Modal Absorbing Boundary Termination Condition for the Application of the Finite-Element Time-Domain Technique to Discontinuity Problems in Closed Homogeneous Waveguides

    Article • IEEE Transactions on Microwave Theory and Techniques, March 2004, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Tian Hong Loh

  110. Photonic bandgap surfaces with interdigitated corrugations

    Article • Electronics Letters, January 2004, the Institution of Engineering and Technology (the IET)

    Dr Tian Hong Loh