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diff --git a/Source/FieldSolver/SpectralSolver/SpectralHankelTransform/HankelTransform.H b/Source/FieldSolver/SpectralSolver/SpectralHankelTransform/HankelTransform.H
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+++ b/Source/FieldSolver/SpectralSolver/SpectralHankelTransform/HankelTransform.H
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+/* Copyright 2019-2020 David Grote
+ *
+ * This file is part of WarpX.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+#ifndef WARPX_HANKEL_TRANSFORM_H_
+#define WARPX_HANKEL_TRANSFORM_H_
+
+#include <AMReX_FArrayBox.H>
+
+/* \brief This defines the class that performs the Hankel transform.
+ * Original authors: Remi Lehe, Manuel Kirchen
+ *
+ *
+ * Definition of the Hankel forward and backward transform of order p:
+ * g(kr) = \int_0^\infty f(r) J_p(kr r) r dr
+ * f(r ) = \int_0^\infty g(kr) J_p(kr r) kr dkr
+*/
+class HankelTransform
+{
+    public:
+
+        using RealVector = amrex::Gpu::ManagedDeviceVector<amrex::Real>;
+
+        // Constructor
+        HankelTransform(const int hankel_order,
+                        const int azimuthal_mode,
+                        const int nr,
+                        const amrex::Real rmax);
+
+        const RealVector & getSpectralWavenumbers() {return m_kr;}
+
+        void HankelForwardTransform(amrex::FArrayBox const& F, int const F_icomp,
+                                    amrex::FArrayBox      & G, int const G_icomp);
+
+        void HankelInverseTransform(amrex::FArrayBox const& G, int const G_icomp,
+                                    amrex::FArrayBox      & F, int const F_icomp);
+
+    private:
+        // Even though nk == nr always, use a seperate variable for clarity.
+        int m_nr, m_nk;
+
+        RealVector m_kr;
+
+        RealVector invM;
+        RealVector M;
+};
+
+#endif